A start to sum it up is a nice wrap up over at PC World. My favorite so far is from mobilecrunch which includes this gem:
Typing on Windows Mobile 6.5 is an absolute miserable chore. How bad? Every time we sat down to review this thing, we got so frustrated with the keyboard that we had to stop. We. Hate. This. Keyboard. Typing on this keyboard is like sewing with your feet. Even with a stylus (do not even TRY typing without the stylus. You can not. Your fingers will hit every button except the one you intend to hit), an awkward lag between letters and the overall clunkiness made us want to rip out our hair. If nothing else did it, typing in Windows Mobile 6.5 immediately killed the entire OS for us.