Scott, I have limited experience and ability to rate the quality of these sounds. But the demo at M-Audi should be is indicative of the sound one might get. There are a number of custom possibilities in the drum kits. No recording ability, tho.

My understanding is that you would like to restrict backing to drums. You can DO that in OMB, but only in the context of "styles" -- i.e. you could use a Yamaha-type "style" and mute all but the drums. That's if you want to use Yamaha styles as the basis for your work.

With BIAB, you can vary everything quite a bit more -- have you used it lately? The newest version is pretty impressive, I think.

It would seem to me that a "drum machine" might at some point restrict you somewhat more than software would -- but of course if you are not using computer generation for your voices/backing then a standalone module for drums would seem less troublesome. I looked at some (like the less expensive BOSS units) but I am determined to use smapled voices via the computer, so I am sticking with software solutions for now.