Matt,
I've been using the pronto for 3 weeks or so now. And I'm pretty happy with the touchscreen, no problems im sitting in my chair. The only complaint about its handling is when i'm lying it's just a bit too heavy for a vertical one-handed holding position ;) but I can deal with that.
The scrollbuttons are indeed the buttons I sometimes need to press twice or three times, but with the software you won't need to scroll that much again or you can use the hardbuttons for scrolling (I think).
Phil