Excellent story.
I, generally, use RealDrums on my songs and then layer my playing & that of other collaborators in a song. I often add Real Tracks to augment - not many but often.
I used to use a "real" drummer to record multitrack drums for me but that was a problem as he'd have to be available as well as interested in the track & those two aren't always a given. The gentleman is also a superb rock guitarist.
A couple of years ago wrote a song and prepared a draft/sketch of it using RealDrums, my bass playing & my guitar playing. I played it for the drummer and he liked the song. He's a stickler for quality, said that he liked the song and offered to play guitar on it. I reminded him that it was a BIAB RealDrum track, (with some EQing to address excessive cymbal noise and too much kick click with not enough thud), and he responded that it was fine and reiterated his offer to play guitar.
That's a superb drummer - who also does excellent multitrack recordings of him playing his kit - happily playing on a RealDrum based song.
On a recent track he did the same - he had some suggestions about EQing the RealDrums to suit the song but was, again, happy to literally "play along".
I'd LOVE RealDrums to be split into stems for a more tweakable sound but I also understand that many, many BIAB users are happy with what's happening in the BIAB mixer. IF RealDrums were more tweakable in the Audiophile version I'd definitely buy that.

Cheers
rayc
"What's so funny about peace, love & understanding?" - N.Lowe