Obviously the sound quality of audience recordings varies wildly, but myself and many others here will agree some of the best boots are audience recordings! IMO you get a more natural, ambient sound, the sound has room to breathe. Soundboards can be a bit flat.
You know about the Mike Millard tapes, right?
https://en.wikipedia.org/wiki/Mike_Millard
https://en.wikipedia.org/wiki/Listen_to_This_Eddie
The 1979 Copenhagen shows are great ones as well.
It can take a while to develop 'bootleg ears' when it comes to audience recordings, but you should seek out some of the better ones, you're missing out if you don't! Cheers!