Pros: Very good price and easy to use.
Cons: Replacing the broken part... but now it seems to be running great :)
This mixer is plenty sufficient for mixing small quantities at for a limited time, but when any sort of work needs to be done that is more demanding, this should not be your first option. This mixer is known for it's worm drive gear giving out. When it broke on my mixer, I found a new one at Constructioncomplete.com. Although the part appeared very similar, it seems to be holding up better than the original.
Now that I've experienced one worm drive gear breaking, I don't think it will happen again. I've noticed that a lot of people online give this mixer a bad review, but it seems to me that most of these people were expecting some sort of industrial grade mixer. You bought the mixer for $100! Don't be so upset when you break the drive; after all, you did try to put 5 bags of cement in the drum...;)
I think the next mixer I buy will definitely be more capable, but as a DIYer, I can't complain about this mixer for the price. I've convinced a couple buddies of mine to get this mixer and neither of them have experienced any trouble with it.