agreed, w800i owner. had the k750i for about 5 months. had some problems with it reception wise (just my k750i) and decided to upgrade it to the w800i.
awesome phone, i like the joystick and metal menu/walkman buttons. i like the camera lens design too, makes it look like a real camera (well it is, but on a phone).
but overall very similar to the k750.
i don't like the new earphones too much, when i try to use it as a headset, u have to clip it to something near your mouth. with the k750 it's easily adjusted.