BIAB is a great tool, IMO to help write songs with, or if you need a "band" to back you up for playing live and you're the only one playing.
I use it as a base to help write the song, then I use it in sonar to write temporary backing tracks to fill in while I or others I am collaborating with create the real tracks for the song. for example, I'll create the song in BIAB, then put the drums, an acoustic, maybe an electric and maybe a piano track from BIAB into sonar and then share the project with my collaborators. they use that project to play along with to record their part of the project. then when I get their real tracks, I delete the BIAB tracks and we have a real song to mix.
it's quite powerful, actually, even if it looks clunky and amateurish.
I'm still on BIAB 2012, tho, I've not upgraded for a few years now.