I have used BIAB for years (from the old DOS days). It is really easy to set your key, tempo, rhythm pattern, and enter your chords on the grid. In a couple of minutes, you can have the whole song sketched out for you. Really, just a few minutes.
Since I started gigging in a cover band, I just download the original tracks and play along with them. But I used BIAB for many years for practice at home. The sounds have improved over the years, but still, a midi guitar just comes up short compared to the real deal, IMHO. BIAB used to be my main trainer because I could slow down and/or loop the midi file without losing any quality in the sound. My new guitar trainers and software can do almost as good as a job with audio files. So, for me, playing along with the original audio tracks works out better.
It's been a few years since I upgraded now, but BIAB was always stronger in the Jazz areas than in my field - Rock. BIAB is a great composing tool and you can sketch out a song, chord progression, etc... with minimal effort. I think it's worth it. But I also use other tools, and more recently, I'm just playing along with audio files for my cover band practice.
Depending on your needs, and the type of music you intend to play, you might consider Guitar Pro. There are thousands of Guitar Pro songs for download on the internet. Recent versions of Guitar Pro have moved more to the accompaniment and composing features than in the past. Also, they are using 'real' sounds now and not just the simple midi synth of your computer. I have used that program in the past too. It's a good program for me if I can find the song already posted on the internet. In my version of Guitar Pro, it's not too easy to set up a song from scratch. BIAB is much easier in that respect.
