I own the Trigger IO and I recommend it. It has 10 stereo inputs. If that isn't enough, you can split a stereo input into two mono inputs (for example on the bassdrum or the toms, where you usually only need mono trigger).
The Trigger IO is working great with AD, but you have to do a little bit of tweaking to get there. But once that is done, the resonse and dynamics are really great. Feels like playing on an acoustic kit ...
Just remember that the Trigger IO doesn't have any internal sounds, so you have to fire up your PC even for a quick jam.