I always thought the Speedstep technology was optional. If you really notice the slowdown in performance, you can just opt for full speed, and use it for less time (battery is drained faster).
I've really wanted one of these since they were introduced, but only want a model with a keyboard built in (unless a tablet-only version presents itself as a superdeal...)
handwriting recognition is their biggest boast, I guess.
I imagine if you use a tablet for anything else, (photoshop, flash, etc...), you'd really like it.
I'm always looking for a used one, since I don't have any urgent pressing need for one myself.