I don't really go to shows that other tapers are generally at, but I think either way, the rule of the road is bring the tools for the job, i.e., both if you can. A clamp shouldn't add too much extra space in your bag.
One alternative that is also nice, depending what venues you go to, is to get a clamp with an extension bar like the Manfrotto 099B. I use that frequently, along with the shorter extension bar. That setup has huge advantages when the venue setup works - with a 7' pole running off of a balcony rail or whatever that is already several feet high, you can get over 10' of height, not have any crap on the ground to get knocked around, and if there happens to be a ton of people with stands (again, something that doesn't happen to me but apparently does happen to you), I could just as easily clamp it somewhere else.
Also less bulky to carry, too. You can't use that 100% of the time, but I find that at the venues I go to, I can get away with that 90% of the time.