Bit of a sticky issue this one...
Letting walk-ons with top-level gear go up against rental customers playing for the first time is, in my opinion, bang out of order. I've played at sites like that and no matter what your intentions are, once the adrenalin gets going you end up cutting loose at the poor punters when they don't have a chance of matching your range and rate of fire. It spoils their day and gets you into bad playing habits, so I don't go to sites like that any more.
On the other hand, when you go out with your non-serious player friends/colleagues etc. for a day, it's a nightmare having to use a site gun if you're used to something that's accurate, reliable and doesn't come unscrewed in your hands.
Solution - do what I've just done and buy a bog standard inferno. It's no better than a site gun so you get to use it, but it hasn't had the $£%^ kicked out of it by thousands of punters so it won't conk out at random moments, shred paint etc. I wonder when our next 50-person office&friends do is....