Recent versions of garageband have a "virtual drummer" that can "follow" a midi song and provide accompaniment in one of several styles (e.g., "rock", "pop", "reggae", ..), and with a 2-dimensional high-level control ("complexity" and maybe "volume"?). It's really simple if you want a scratch backing track.
Does Reaper (or maybe another VST-plugin-accepting system) have a replacement that works with this same high-level control?
All the drummer plugins I've seen are about the recording quality of the instrument, and have you program them with MIDI, which is a lot lower level.