the GUI is the clue as far as i'm concerned. with RB you can see everything up front. you can see all the separate tracks - as many as 48 which is many more than BIAB.

rather than keep regenerating tracks at random in BIAB hoping you get it right and then freezing it, you can generate alternate RealTrack 'takes' in RB and then with them all in view cut and past the bits you like to produce exactly what you want. and if you want to replace a short section multiriffs allows you to generate seven different versions and choose the one you like.

different windows are so useful - chords, mixer, tracks, all more easily interpreted and easier to tweak and work with than BIAB.

BIAB is amazing but to get it to do things other than its basic auto accompaniment function you need to dig down into its internal workings.

just read some of the advice as to how to do things that run to almost a page on the BIAB forum - look at how people are still having trouble with the mixer and utility tracks. i often post that what they want to do is so simple in RB.

as i said the GUI is the clue - everything you want to do is there in front of you. and of course you get the full functionality of BIAB for generating midi, RealTracks and mid supertracks.

rough out a song in BIAB then do the heavy lifting in RB. the two programs work amazingly well together.