Variety is the spice of life. On guitar, if I know the tune, I play along in any key. On banjo, different story; e flat demented gives me problems, so I simply back off and listen.
I get irritated by someone playing along when they clearly don't know the tune, it's like a bodron player who just has to bang away on every tune from Henry Martin to Ava Maria. Of course, the good ones don't do that.
Another thing that bugs me about sessions or jams whatever you call them,people who just decide to do two in a row when the rule is one at a time.One each then one together.
I don't do many sessions, the egos get in the way of a nice gathering.