Pros: Efficient, quiet, less wear & tear on the clothes, great cleaning, less drying time.
Cons: Overall front loaders are slightly more trouble prone than top loaders.
Seems to be a lot of confusion about the HE3 designation. It applies to several different models. Also some people seem to be confusing HE3 with HE3t. We have had the HE3 model 110.42822201 (model number is on sticker that is visible when you open the door) for 4 years and are VERY happy with it. The Kenmore front loaders with model number starting with 417.xxxxx on the other hand have been an absolute nightmare for a lot of people. Ours does a great job of cleaning...quietly and efficiently. A review of several appliance repair forums/blogs shows that this particular model has very few problems, but there is one issue that has appeared three times...knocking noise during spin cycle. If you are at all handy I strongly suggest you tackle this yourself (I just got done doing it). The problem is the 15/16ths inch nut in the center of the large pulley coming loose and allowing slop between the spindle and drum/basket. This nut is easily accessed by removing the back panel. The whole deal is a 20 minute job tops!! Why do it yourself?...because an incompetent/dishonest service tech can easily turn this into a $500 to $800 repair by claiming the bearing and sleeve are shot, which requires replacing the entire stainless interior basket assembly...and Sears won't give you squat in the way of standing behind the product. If you have ever worked on a top loader, you are in for a pleasant surprise with these front loaders...great access to all the key parts, no transmission in the way and much more intuitive design.
You do need to leave the door open an inch or so between loads so it can dry out/avoid stinky smell. It's just basic laws of nature at work. Your old top loader didn't need to have a waterproof seal on the lid...if it did, you would have had to leave that lid open also.
By the way, the sales pitch regarding higher spin speeds resulting in much less time required for drying is absolutely true! You will be amazed at how dry the clothes feel coming out of the washer.