I don't need/want fancy built-in samples or anything, but supporting piezo triggers and dual-zone cymbals is a must, as is variable hat pedal support. I'll mostly be using it with Logic's Drum Kit Designer (which accepts hat pressure via modwheel or via VDrum's protocol which is also what my current Alesis piece of shit uses).
And, for reference, here's the list of cheap drum brains that have disappointed me, and why:
- The Ion IED01 (which was made by Alesis)
- The Alesis one that's in the TriggerPad (which was actually pretty okay except the hihat protocol only worked with BFD, which is terrible)
- The Alesis one that's in the TriggerIO (which worked pretty okay except it started sending spurious MIDI events, and when that wasn't enough it recently decided to start sending spurious USB events that made my computer go completely haywire in the middle of a recording session)
If I were looking to just build a new kit from the ground up I'd be considering the VDrum TD-4KP but I already have a bunch of drum triggers and mounting gear and so on. But it seems like most of the standalone drum brains worth looking at are even more expensive than that complete kit, so...