I went from a MDA to the 8100.
I LOVE it!
I think the suretype is actually easier than using a qwerty keyboard. I can type e-mails and texts with one hand and do it pretty fast.
Of course, everyone has different opinions. I was lucky. The IT guys at work had Pearls so I borrowed one of theirs to play with to see if I liked it enough. It gets a little better every day. (I keep finding new cool things for it.)
Your mileage may vary but I love mine.