I have used Palm Tungsten, SonyEricson p910, imate jamin and imate sp5m. I have been using sp5m for about 6 months now. I am very happy with my phone. I paid 10k INR in Bangalore Bhartis @ Jayanagar (next to Sangeetha).
The phone has a good 1.3 camera, EDGE, mp3 player and a SD external memory card.This was my second microsoft based phone. The dashboard it offers is stunning. I sync it with my outlook on daily basis. Moreover it has EDGE which downloads my mails and shows it on dashboard.
The camera is pretty fine but I hardly use it. With dedicated buttons for music, it is a great add on.Battery life comes for max of 24 hrs only !! But it can be charged thru USB cable connected to the computer. it is a generic USB cable which is cheap and is readily available. The cable comes with the box.
Wifi feature offers 820.1 G connectivity with is very fast. I have installed skype on my phone. Skype on sp5m works on EDGE and on wifi. The voice clarity on wifi is XCELLENT !
With Microsoft as OS, you can expect some bugs but arent any major ones. The date and time gets reset very often after I upgraded my firmware.It has a 195 MHZ CPU!! My first computer was a 486 - 75 Mhz !
Lovely Gizmo called a smartphone.