And I play live for a living. I also play pop/rock/country music (though I'd love to play jazz, it's difficult to make a living doing that around here). I want it to sound right for the audience
I'd just lie to add a little bit to your excellent comments. First, I'm not sure who the "typical user" is for BIAB. I'm pretty sure who PGMUsic thinks it is, but I am not sure that is really correct. I know they are a small company that cannot afford to spend millions every year on market research, so this is not intended to be a criticism.
I do use BIAB in the "idealized" way -- using it as a "backup band" for a solo live performance. But that probably happens once a year. The rest of the time I play with live bands. Here are the things I REALLY use BIAB for -- and I absolutely agree it is an indispensable tool bordering on the magic:
1) Wood-shedding. That's at least 8 hours a week with some combination of BIAB songs and Jamey Aebersold tracks.
2) My own education. Studying these various styles has made me a far more complete musician. And I've only scratched the surface. Even styles I would never use in my playing or arranging, I listen to carefully. A person can never understand too much music.
3) Teaching. Repeat my point 2) for teaching younger students. I will take a simple, familiar song like "Itsy Bitsy Spider" and then put it into 8 different styles. I give the students a listening worksheet where they come up with a name for the style, identify the instruments, and try to describe what makes that style different from the others. Then we discuss/debate. BIAB is unbelievably powerful for that. These sessions might last 30 minutes, and every time, the students are 100% engaged -- because it really is magic. Music is magic. BIAB is magic.
All three of the above can work with MIDI or RT. Makes little difference.
4) I do play a duo frequently where we use a lot of MIDI. I tend to take the MIDI straight out of BIAB because I have become competent at jumps, hits, etc. My partner tends to push the MIDI into a DAW and edit it further. That has to be MIDI because he runs it through a synth live at the show and will adjust instruments and balance while we're playing.
5) My arranging work flow described above. That must be MIDI.
A final general comment, in case anybody thinks any of this is negative toward PGmusic or BIAB. In a 40+ year career, all of it was spent developing software professionally, managing software teams, doing systems engineering for hardware and software, or selling computer-based solutions. In all that time, there are only 2-1/2 software products that really amazed me. That is to say, there are thousands of really good software products, but in 99.9% of the cases, it is completely obvious how the software was developed and how its core algorithms work.
The two-1/2 exceptions are:
BIAB - From the very first version I saw until today, I am still amazed, and still don't fully understand the "intelligence" it contains.
Melodyne - Another amazing program. With Melodyne, I do understand the algorithms at a conceptual level, but the results are still amazing.
And the half-magic program is Izotope RX4 (or RX5 is now available). I understand it, but it is still genius.