We visited The Nash for a free ASU student performance. It was great. It was free! The venue is pretty low key and located in a great part of town. I really wish we'd visited earlier than we did, as we'd definitely return, were we not moving out of town.
I can't really speak to the service, as there wasn't any. Well...other than the phone call I received after leaving a message. THAT was great -- they called back promptly and left me a message with the answer to my question. I imagine ticketed events are probably a little more involved, as they have a drink menu, at least.
If you're thinking about visiting, I'd suggest it.