then u don't know about k850
camera of w800 is much simile to k750, main difference is k750 got Auto Focus.
anyway auto focus sux in k750 because u usually miss ur shot, that auto focus take time to function
w810 got excellent sound quality with Walkman, better than k750s mega base function .
but phones above k800 got superb camera and sound as well, no phone can beat the camera of k850, auto focus is improved and can take good pictures in dark with superb flasher. same as Sony Cyber-shot cameras.
that's all i guess