I use these guys and have had no trouble with them.
Downtime? I've used them about a month and had 100% uptime thus far, so they've already beaten every other VPS I've ever tried (among them System in Place, Satisfied Hosting, FutureHost and others).
Haven't had a reason to use their support yet though, so I can't comment on that.
In all, it was a pleasant experience. Instant set-up, a nice blank OS install and I'm getting the performance I would expect out the box.
5 Stars.