If you have an E-Drum set that sends Poly Aftertouch to choke cymbals (Roland and Yamaha both do this), you may have noticed that choking does not work with NI drum libraries.
It looks like this is a bug in their script; fortunately I found a pretty easy work around. Set your drums up to map to the Default preset and do not try to use the 'Roland' or any custom preset.
I have reported the issue to NI. I discuss the issue and the workaround in a bit more depth
here.
This may be old news, but I couldn't find it anywhere.
Andy