Just for an opposing opinion, I've personally had much better success with Site5 than my prior host, uptime has been great, support has been reasonably good (given cost, I don't ask for much!), and price for feature it's extremely competitive.
I was actually on DH for a few weeks, bailed because of some of the issues that WP users started running into (CPU usage limits, etc.) and the lack of decent CP, and seeming lack of interest on improving certain problems/issues (they do have a "vote for improvements" system, but the things that I was asking about had be 'in the queue to fix' for a year and a half and still hadn't been dealt with...).
But that's me, and my experience. I do recommend DH and Site5 to people -- they are where my search for a price-for-feature competitive host ended.