I must say, overall this is kicking ass and I'm getting hopeful that Battery might finally be useable for me!
The problem is that once a sample is loaded it only plays in mono, left channel.
Other than that, I'm thrilled to report/confirm drag-n-drop from both the Explorer and (Ctrl+Alt) from the arrangement is working great.
Also the custom note-naming in the midi editor is fantastic, I've wanted this for a long time. Between all of this, the "drum note" view for the midi editor, and Input Quantize I think Reaper's looking pretty good in the beat-making department! Ableton is on very thin ice (though I'll probably be keeping it around if only for its iTunes import capability).
Can anyone confirm the mono triggering?