welcome! i personally found the p2 touchscreen to be sluggish and unresponsive. I see the touch as a wifi device foremost and music player as a close secondary function. i have never used a d2, but its highly regarded around here. as for the s9, im as anxious for it to come out as anyone else. hope that helps.
personally i love mine. once it's jailbroken, it's unrivaled. i honestly don't think the SQ is horrible either. sure, it's not nearly as good as say the Zune or the Clip but it's quite decent when paired with my UE 5's.
if you look around you can get the first generation itouch's for less than $200 easy