Great discussion! If I may, I'd like to focus on the other aspect mentioned by Ed in his kickoff post-- the "constant noodling in between songs."
That's something that has always driven me crazy, whether it's being done by the bass player or a keyboard, uke, or guitar player.
I have played in many different configurations of bands throughout the last 53 years (most notably with my three wonderful brothers from 1970 to 1986), and I've always tried to stress to my bandmates that 1) the first audible notes that the audience hears for the evening should be the first notes/chords... of the first song... of the first set; and 2) there should be no doodling in between songs or otherwise "giving away" each successive song as we make our way thru the list.
Regarding the first point, I've always felt that once patrons have begun to gather, it's time to limit the handling of instruments to a quick check of tuning-- but I very much do NOT like it when a bandmate or two start audibly "running thru" some tune five minutes before start time, especially if it's a tune that's not on our list, such that they don't really know it well, and just sort of wing it for a minute or so, and then stop. To me, that takes away from the excitement of striking the first chord of the first actual song to start the actual performance. One time in particular, as we completed our setup process in a bar setting, a popular song came over the "house" radio speakers, and our bass player proceeded to play along with it, thru his amp, all the way thru, and honestly I found that to be cringe-worthy.
Regarding the second point, I'm always disappointed when a bandmate starts audibly "spot-checking" a signature riff from the song that we're about to do next. I used to tell our other guitar player, "Please, don't give the song away!"
Well, I'm tempted to add here the now-predictable expression... "Now, get off my lawn !!!" But seriously, I dearly love all of the people involved, but it just seems to me that a performance can be diminished by band members' tendency to fidget.