Well, if I were you I would sell the Diamond and get the TP

This because on the TP you have the option for a Micro SD card, which I think is SUPER!!!! Because I use the TP as my MP3 player also, and I got all of my pictures on it

So the Micro SD makes the phone super!
Also it got the SlideOutKeyboard, which I find is great!
The Keyboard adds some size to the TP but I find that it actually isn't so big, it's rather comfy!
The Touch Pro also is delivered with a better battery! I've heard that sometimes you got to charge your Diamond 2 times a day! This is sick! because I go two days, with normal use, without charging!
But if you don't mind the on screen-keyboard, the 4GB internal store, the glossy back (Which isn't on the TP) and the poor battery, then I would stick with the Diamond