We have a couple of servers at NatNet and have been very happy with them for the most part.
Our blog hosts are hosted there and a tgp server with over 100 active tgps. Support is fast... post a ticket and have an answer within minutes. My only complaint is that sometimes the techs don't read the whole ticket when they switch shifts (or something) and sometimes don't do exactly what you asked for in the first place... but I think the majority of that can be cleared up with precise communication... something I sometime FAIL at.