1 I've seem Campy play a dozen times in the last year and not once did he use an RI.
2 He plays plenty of Power chords (try and Lisen to "Helen Keller's Waffle Iron" for an example.)
3. Jim does hot bias his NOS tubes in his original BF and SF Princetons and switch the speakers.
4. He always goes through the PA.
5. I've seen him play with Organ and Saxaphone along with his Trio.
6. Stephan Crump's Bass is Stand up running through the PA and an Aguilar 500 watt 4x10 amp
7. Tony Mason rocks, his style is all over the place and he slaps those skins when the song calls for it
Great shot! A Princeton can definitely be used for gigging. I have used a Tweed Deluxe and a Princeton Reverb in the past and for most rooms, if the drummer is not a complete animal, it can handle it. Of course, best case is to throw a SM57 on it and put a little through PA-on-a-stick or whatever sound reinforcement is available.
I have witnessed so many live acts that use amps way to big for the room and their tone just sucks. I personally do not like od/fuzz/distortion boxes for main rhythm and in many cases you have no choice with too much amp no matter how good the amp might be.
It takes a little time to adjust to smaller amps but once you get used to working the amp and the room your tone becomes better and cuts through the mix better.