One last point, just to put this out there. They're easy enough to control if that's the sound you're looking for. Buy a volume pedal so you can quickly mute the guitar when you're not playing, and make sure you rehearse with your amp at gig level and figure out how to control it mid song by changing your position relative to the amp.
But there are plenty of players who make them work live. Willliam Reid? Ok, that last one maybe didn't care so much about feedback. Elliott Smith, Bernard Butler and Daniel Kessler from Interpol are all more modern players I've seen play big venues with cranked ES330s or Casinos, Paul Weller's another good example. There's a great made for tv film of various rock and roll legends in the early 70s: Chuck Berry closed the show with a 330, turning to his amp half way through to give a hefty twist to the volume knob - that thing sounded awesome once turned up. Check out the Beatles gear book for the back line they were using by the time John and George were using Casinos. There are plenty of good examples of people who have used Casinos and ES330s at very loud gig levels without any feedback issues they weren't able to cope with.
