WINDOWS Mobile 6 Professional running on ATT. GUI look/feel fine, ergonomics fine (read all the positive reviews), but phone has problems w/ autosync, email not updating, freezes. Battery life very poor. I'm an occasional user, mostly use phone commuting to/from work. I'm very unhappy with having to reboot the phone multiple times a day. Upgraded o/s from 5 to 6 with little or no improvement in freezes. I'll wear out the door to the reset button. Fortunately a company phone, so IT will get me a new one to try. Curious to see if a second phone will still encounter all of the o/s issues. Would like to try Palm o/s but that isn't a choice with IT.