I've been using the mighty mouse since they came out. One at home and one at work, and have had no real problems with them, bar the reflective surface issue, but seeing as I had a mouse mat anyway that didn't really affect me too much. I was very cautious when I heard that Apple were making a two+ button mouse, but now if I go back to anyone else's one button mouse I find myself trying to right-click then wondering why nothing is happening! Just depends on your personal experience I guess!
A Look Back at Mighty Mouse