So, I went over on Saturday.
It was pretty laid back, as somewhat expected. Almost as much a get together as a rehearsal. The surprise came about 20 minutes in, when the drummer's wife (we were at his house/studio) came in and asked if anyone was allergic to onions, as she was cooking dinner.
Appears I got the gig, pretty easily. The comment that confirmed that was, "Wow, its nice to have a bass player that plays things right. You coming back next week?"
I felt pretty good for having spent about 4 days cramming the songs.
There are actually a few pretty good players in the group, and no absolute stinkers (its a 7 piece - drums, vox/rhythm, lead/rhythm, rhythm/lead, keys, percussion, and bass. Most of them sing, and decently. And a sound guy who occasionally doubles on drums or percussion, as needed). Keys player is a locally busy jazz player, who does this as a laid back side gig, to do more rock stuff, just for the fun of it. One of the guitarists is a bit of a wanker, but they seem to have him fairly well reigned in.
All in all, worth it, and looks like I'll keep playing with them for a bit. Of course, I have a couple more auditions over the next couple weeks, so we'll see how those pan out, but this is very laid back until they start gigging again (probably a couple of months - want to make sure things are tight prior to).