Pros: Free time instead of wielding the vacuum cleaner
Newer models fixed some of the mechanical issues
Cons: Batteris don't last 1000 cycles in these units.
Expensive to replace
This review covers the IRobot Roomba 4100 to 4300 , a mooded red vacuum disk. I bought this one for 90 USD refurbished at Amazon, to replace the Roomba Sage, that we had running at our service for roughly a year. Most reviews are from glowing first time users. I thought it might be useful to give you a one year verdict.
The refurb Roomba comes with following contents.
Red Roomba with 2 functional buttons: Clean, Spot.
7 charging station
IR barrier to limit field of roaming for roomba
couple of filters and a 'cleaning' tool
90 day warranty
As such it lacks some of the more expensive units accessories:
3 hour floor loading station (a tad more practical)
Max button (which we never used on the more expensive unit anyway)
IR remote (again, never used)
higher quality plastic body (matter of taste, but I like the green version better)
1 year warranty (which if you are first time user is recommendable, unless you are crafty with screw drivers and aircans)
This unit replaced our first one, a Roomba Sage that I gave as a christmas present to my wife.
It worked.. she was thrilled !!
We were about to move into a new home with all hardwood flooring and the prospect of vacuuming the cereal 'droppings' of our kids each morning to protect the floor didn't thrill her.
This little marvel of technology was supposed to do it all.
We tried it in our last house on carpet and hardwood floor and the family had a great time watching 'Karlson' zig zag around the house busily cleaning the floor. (Once you buy it, this little machine expresses such an 'cute' ant like busy behavior, that you can't avoid nicknaming it).
How well does it work?
My detailed wife's assessment: Cleans about 95% of what she would get, with an added bonus underneath tables, chairs, cupboards and beds, that he is low enough to crawl under. No more getting on your knees to vacuum dark corners. The red entry level model seems to share the same chassis and logic with the larger unit we could not detect a difference in quality of cleaning
The fun part: With a push of a button you can send it to work every day. We have about 1100 sqft for this little bugger to clean and it busily zips around each day.
The patterns look 'random' and you will see it crossing it's path quite often, but going for about 2 to 3 hours it will cover the entire floor over time
Corners: A little extruding rotating brush takes debris from the corners, even if the vacuum doesn't get in.
The Roomba has a little laser distance device on one side, so it can 'feel' it's way along a wall, and will go parallel close up actually doing a good job along the walls.
Clean: Will send the unit on it's cleaning mission
Spot: Will send the unit into circular motion describing and expanding and then shrinking circle. Neat feature: if you are against a wall and use spot function it will move in a rainbow fashion in and out vacuuming in a half circle. Very handy feature to clean underneath breakfast tables etc.
Max: Supposedly adds extra power to the vacuum, we haven't found this function to add much to the cleaning power. Practically never used it, so we happily gave up on it when we bought this replacement unit
IR Remote: You can give commands to the unit via IR. Also practically never used,as the typical cleaning operation would go something like this: Pick the Roomba up from it's base station, carry it on it's flip out lid to the break fast table. Start it in spot function to clean the largest mess around the kids side. This function will stop after completion. Send the Roomba around to the rest of the house by pushing 'clean'. In other words: You don't need the remote. Some of the later remotes have a timer on them to send the Roomba automatically. That might be a nice feature. We still wouldn't use it, as it is easy enough to send the unit going when you leave the house. A timer combined with the base unit below, might enable to have you fully automate the cleaning. I doubt you would be satisfied with that combination though. If nothing else you need to empty the vacuum container every 3-4 days and searching for the remote is not funny. Also this system only works if the unit finds it base station with 100% accuracy. So we don't miss this function of the higher end units either.
IR Barrier: Nice feature if you want to limit the Roomba to one room without closing doors and such. Just send a IR ray with this unit and the Roomba will see it as a wall. I recommend to have at least one in order to block off 'sensitive' sections of the house or limit the roaming field .
Loading: The charger that comes with this unit is a plug in 7 hour charger. While the load time has really no significance (you typically run this unit everyday but just once), the floor base station is easier to handle. The Roomba parks on it and two pins at the bottom start charging the unit.
Supposedly the Roomba automatically returns to the base unit when his battery is low, such automatically recharging at the end of a cleaning cycle. It is interesting to watch when the Roomba tries to climb the base station. Sends a sensation of a mating ritual. Very funny to watch. We have found though, that unless you are prepared to have your Roomba in plain view in a single room, chances are he is not going to make it back to the base station and rather ends up sending 'lonely' beeps from where he ran out of battery in a distant room.
So we continued using the base station of our old Roomba. One thing I would have missed in the low end edition.
Vacuum function: So apart from the cuteness and the high tech appeal of 'semi intelligent' behavior. How well does it clean? We found it to be a match to a regular vacuum machine, maybe not quite as intense as a regular high power Hoover, but overall results are WAY better on carpet and hardwood floor, as you vacuum about 15 hours a week and that includes most 'dustbins' at hard to reach locations.
Vacuum container: Will last about 2-3 days depending on the dirt level you catch. First couple of rounds you will be amazed how much the unit can catch from a supposedly 'clean' house. Just do your regular vacuuming and then send the unit behind it...
She loves it:
Our regular vacuum is pretty much retired and we run the unit each morning after breakfast. Roomba diligently cleans up our kids cereals and dust under coffee table and sofa. (As long as you have a couple of inches in height for him to crawl under).
I hate it:
Well actually I love it too, I was intrigued by the simplicity of electronic resulting in high quality of work.
The sensors on the unit will prevent it from running down stairs, when the little bugger gets caught in a dead end it will back out and an engineer will spend some funfull hours exploring some intelligent functions of the unit by building 'race courses' and traps. Also after a while you will adapt your habitation layout to make it Roomba fit. There is two things the unit doesn't like. Cupboards which are high enough for the disk to fit under, but not the protruding IR sensor on top. I have found that the unit can actually wedge itself then and get stuck. (Solution are a couple of small wood strips glued under the cupboard). The other one are loose cables. The unit will suck them in and get stuck. No problem with removals and no damage done, but nevertheless it gets stuck. Other then that the unit is intelligent enough to switch itself off when contained in an unescapable spot.
So what is to hate then?
With all the ingenious programming to have the unit cover all floor space, there is some sloppy engineering on the unit, leading to the dreaded 'whirly' dance. The unit moves forward then goes into circular spin, stops, backs up, does it again and then repeat. This seems to happen quite regularly, as you will find in may internet forums. Reason are photo sensors in the wheel case. There are little toothed wheels rotating through an infrared beam that shines onto a sensor, giving the unit motion information. If the wheel gets' stuck' the unit will back up. Well the wheel cases are poorly insulated from dust. Where the cables enter there is actually and opening that lets dust in easily and the covers are butted against each other without a seal or a nudge, leaving space for dust to enter as well.
Doesn't take a major brain to predict what will eventually happen to an optical sensor in a VERY VERY VERY dusty environment.... Yeah.. it will dust up and cease functioning. Nothing you couldn't fix with a compressed air can. The outer sensors (cliff sensor for detecting stairs and sidefiring sensor to follow a wall) are less sensitive and easily cleaned with an air can, but in order to get to the wheel case,it literally requires you to take apart the entire unit and even then there is one screw on the wheel case you can't get to very easily, so you end up loosening about 20 screws on the unit, 'wedging' the wheelcase open and blowing compressed air into it, which sometimes will, sometimes won't fix the problem. I have found on our replacement unit (which was the refurbished red Roomba 4100) that they had closed the wire inlet with a glue gun, an improvement, but I don't think it will be sufficient.It is to early to tell. On the old unit the problem started about 7 month after purchase. I ended up using my hot glue gun to seal the entire gasket and the wire inlet, which gave me piece for about 8-12 weeks at a time. Still no 100% fix.
So this is the Achilles heel of the unit. They should replace it with a magnetic sensor and some steel rotors and the problem would be fixed forever. Minimum I would expect a much tighter seal and an ability to get to it for cleaning without taking the whole Roomba apart.
There you have it: I spent hours cursing at the hardware engineers at Roomba for this lousy detail, while marvelling at the programmers for their ingenious software design.
Would I still buy it ? My wife LOVES it.. what more can I say.. and I LOVE it too, when it doesn't run in dreaded circles.
Seems they have improved the software from a year ago, as it seems to run a tad more 'intelligent', but no fix to the Achilles heel.. So I keep my screwdrivers and air can handy....
Update June 2007: We are on our third IRobot now. Both former models had issues with the desribed whirly dance, but both eventually died as the vacuum motor gave out. The robot is happily running around with an eerie low noise level, not sucking up a thing. So I have to add that motor to the list of under engineered components. Both motors were gone within 15 months.. just outside the warranty period.
The latest one we bought seems to try to address the issues. The wheel casing is much more tight (haven't opened it up yet, as we are still under warranty, but I would guess they are STILL using optical sensors). The vacuum motor has definitely changed, as the noise level has gone down dramatically (which is VERY nice) and has a different frequency to it.I hope this engine is also more robust then the earlier ones. Keep fingers crossed that these new models are not going to last just past the warranty period. If this one breaks down, I'll go competitive.
Update July: Sad to announce that the THIRD Roomba has died. You guessed it, the new vacuum motor that I had so much hope for... it quit working. Only nice thing is it did it WITHIN the warranty period. So I am not going competitive yet, but rather test out Irobots warranty handling procedures. Come on GUYS! You build military robots! Electrical motors don't brake down, unless they are shoddy quality or undersized!
Tip: If you can get an extended warranty plan, based on my statistical sampling base.. Get it ! It'll be worth every penny. That also disqualifies purchase of remanufactured Roombas, as they come with 6 month only. Definitely not to be recommended!
Update September 07: Got the new replacement in the mail. A 4300 Exchange was painless. Now I have the newest generation, which can be noticed by the white strip on the front wheel, which is now an extended range swivel wheel. I did an outside check on the unit. They have changed the wheel cover design again. I still suspect it is the old sensors, but won't confirm until warranty is over. The much troubled vacuum motor seems to have changed again. Sounds less noisy, which is good, as noise in mechanical designs does equal wear.. Subjective impression is that it's sucking ability is also slightly reduced. So far the new one is running for 6 weeks without problems. Let's see how it goes after warranty..
Update September 08: The unit is still going strong, although the battery gave out in the mean time. The latter is to be expected, but a 50 to 60 USD replacement cost for the OEM battery on a 90 USD device, I would opt to replace the entire device, as mechanics have wear and tear. For now I still have batteries from the previous units that gave out. Look for alternate battery suppliers, they range in the 30 USD range and some with extended battery time, which means extended vacuuming..
At last it looks like the product is getting to a durability point, where I will consider repurchasing, rather then switching.
Update July 2009: It runs.. and runs... and runs... seems they have fixed a few of the older flaws in the new model. Batteries in this unit don't hold for a 1000 cycles though.. that would be 3 years... and they definitely break down earlier.. Some of the higher end units seem to have better charging cycles, so the battery lasts longer.