Might want to try fxpansion GURU; apparently what you're looking for is one of it's main fortes:
IMO, apart from the quick editing options, there's two major things in Guru which, especially in combination, make this a kickass tool:
- You can preview drum patterns in realtime/hostsynced. No dragging of MIDI files into your host required, just to see what they'll sound like. You preview them from the browser, which is very convenient. And you can allways go back to the previously loaded pattern, shouldn't you be happy.
- You can preview a variety of sound sources in realtime too. This goes for individual samples, complete kits and "extracted loop content" - the latter being an incredible source of inspiration.
And more specifically, this:
When I saw the locking slots bit so you could load another kit for the unlocked slots... damn! So simple yet SO important to your workflow.
EDIT: Wow. Feed a breakbeat or house loop into this thing and it automatically chops it up, envelopes it and assigns it to pads. It even tries to detect what's probably a kick, snare or hat...