Pros: I got it for free with my cell phone plan.
Cons: Poor reception, bad sound quality, bad interface.
Compared to my old Nokia phone that this phone replaced, the sound quality and reception are noticibly worse: I'm on the same network but I have more dropped calls than I used to, and the phone often renders voices unintelligible.
The interface is poorly designed, too. Several times it has completely frozen (just like Windows does) so that I had to turn the phone off and on again to use it. There are lots of other little annoying things like how when you miss a call and the phone is closed, it displays a big "1 missed call" message on the front and no longer shows the time, so that to check the time you have to open up the phone and press a couple buttons.
The built-in camera is junk, too. At least the battery life isn't terrible.