Solos are great for the genres BIAB represents. It's ridiculous to expect a software not aimed specifically for guitar to do Van Halen chops. My honest opinion is that while some soloists are far from perfect, they are absolutely usable for sketches, demos, backing tracks, place holders and more advanced music with some editing. A track I am tinkering with now, I have a fantastic soloist RT my Mike Durham (3441).

If I can't find something in BIAB, I go to other sources, not because something is "bad", but because I want something different.

But wait, there is more...
There are User Tracks. But that is another discussion.