Well I went for the X1, and having seen a friend's Touch Pro am glad I did.
The X1 is a much nicer looking device (not as wide), and the battery is decent enough for a WM phone. (I tend to charge it every night, but it still has well over half the battery left then. Apparently the Touch Pro will struggle to even make 1 day if its used moderately heavilly)
The screen res isn't too much of an issue - you can download a utility from XDA-devs (cant remember the name yet) which basically chops off the extra width (leaving a black bar down one side) and makes it appear to be a VGA screen to other applications. - which can be helpful if an app or game wont run or looks skewed.
Shame the keyboard doesn't have arrows, but its still very good. You can always use the d-pad for arrows (although I should point out that the d-pad isnt the greatest for games - mainly due to the "up" being a little trickier than the other directions to press.)
An essential download is the SPB mobile shell panel from http://www.sonyericsson.com/fun/
Its free for the X1, and makes the phone far more finger friendly.