The servers do experience uptime more often than not (which is not saying much), but when they went down recently (mid-June 2010), they stayed down for a good week. And though the servers are back up, there are still issues with their configuration (as of late June).
And you can forget about trying to contact someone at the company via phone or support ticket about any issues you may have, servers or otherwise. I can't even say how well customer service and tech support are, because they don't exist (I guess that means they're poor).
Just a general bit of advice to webhost seekers - and this is something that really sunk in while I was dealing with this company - you should never consider any host company whose tech support division/guy you can't reach on the phone.