I find that there are some really good bass tracks in BIAB and a lot of pretty marginal tracks. Most of the bass tracks are pretty generic, to begin with. It depends on the style of music as to how useful they are.
The country and Americana genre bass tracks are generally usable but all require adjustments with EQ and compression. BIAB has hundreds of bass tracks that I have not listened to so I certainly do know everything.

If there is a DI track, in general, I prefer to use that and use Trillian as the amp sim. Actually, I find it is less work to use midi tracks when available.

I think we all ask BIAB to do things that it is just not capable of. You will not find the likes of Billy Sheehan, Marcus Miller, or Paul McCartney in BIAB.

BIAB is a great piece of software for what it is capable of doing. Very little is A list studio quality recordings. Add the algorithms needed to make it work and often one will find "muddy" recordings.

Just my two cents worth.

Billy

“Amazing! I’ll be working with Jaco Pastorius, Charlie Parker, Art Tatum, and Buddy Rich, and you’re telling me it’s not that great of a gig?
“Well…” Saint Peter, hesitated, “God’s got this girlfriend who thinks she can sing…”