< That description seems to say that I can have my playing on the tune, and BIAB will create a MIDI file to see the notes written out? >
No, this isn't exactly correct.

BIAB will play your recording but the midi notes have to be manually input, BIAB doesn't create the midi. The data can be entered using notation, piano roll or copy and pasted from existing midi data. The midi data RealCharts from a RealTrack or SuperMidi Track can be used or a riff copied from a free midi file found on line. The midi can be sourced from anywhere. BIAB can generate midi from a monolithic audio recording but that's more complex and advanced than what we're discussing here.

Once the underlying midi has been added to your recorded track, your recording will play the same as a RealTrack with RealCharts. Viewers can see the notation, tab, guitar fretboard of your recording.

Your recorded audio can be transposed and time stretched by BIAB so it's possible to play your solo at half speed and the tempo will follow if you change the tempo back to normal but it may not sound good.

< Why wouldn't that be a bigger deal to sell the software? >
I agree this is a really big deal that doesn't get the attention it deserves.

BIAB 2025:RB 2025, Latest builds: Dell Optiplex 7040 Desktop; Windows-10-64 bit, Intel Core i7-6700 3.4GHz CPU and 16 GB Ram Memory.