I have just got the K750i on contract and its a superb phone, best phone i ever owned just in front of the Siemens SL45 i had a few years back
I upgraded from the Siemens SX1 and its soo much better (comparing features they both have of course as the SX1 was a smartphone)
The screen looks pin sharp and the 2MP camera looks fantastic, and from reviews they dont think it will be beaten for around 6 months. Everything is very quick through the menus, the photos load quick games load quickly and look excellant (the 3D tennis you get with it is very addictive)
MP3 player and radio are excellant quality and the loudspeaker is the best i have heard, mp3s can be played through it and you will be happy with the result
The size well that amazed me when i first saw it for all the features packed into it i could not believe how small it was and looks very snazzy, All in all i am really impressed
(Never been a nokia fan myself there designs never appealed to me and build quality on the ones i have handled is not up to much)