Tryst is a lot of fun, beautifully decorated (waterfalls!), and outdoor patios which were lovely. I'm not sure it exactly lived up to all of its hype though (or maybe I just hate lines and waiting ;). It was good enough for Paris Hilton as she was there that night (this was her pre-Wynn/Vegas ban). Music was just OK, crowd was pretty diverse and interesting.
If you come to Tryst I would recommend definitely getting on a list (cuts the wait time down though still a bit lengthy) and I'd recommend getting a table and bottle service, especially if you have a large group. It's definitely worth it.
Bottom line, Tryst is the best club I've been to, but given that I'm not a clubgoer I'm not sure if that's saying much