I've read a lot about how guys have Had issues using provided back lines for festive gigs and such, using sans amps to help w crap rigs and things like that. I want to say I've played quite a few of these type shows and they always send their emails about mandatory back lines and minimal switch over times. I've never used the provided heads. I bring my rack, throw it on top theirs swap cables and I'm off. Never once have I been hassled and the soundman doesn't have anything to say either. I will say that I always thought swr to be good stuff but I've used a bunch of their 8x10s and they sucked. Real tinny. They usually provide gk (1001, 800rb ) in my area.