I don't believe it does aftertouch, but I mostly use only touch sensitivity anyway. In all this time, the only thing that has given me any trouble is a little flat-topping if the volume gets too high. But it never quits. I've been doing MIDI since 1988, and it shares duties with some of my old Alesis stuff, most of which has also held up well. I really like the sound I get when I create a song in a 'whole band' arrangement, and it's about the only thing I can use on a laptop that makest the MIDI sound good.
Gigs are fun with it.
I do, however, wish there was some way to do editing. I love it. The presets are great, but can't be changed. At least, as far as I know. The manual is for the Mac, and I'm using it on PC, so I can't rate the manual.