I had one client project on DreamHost, and never again. My experience with them was that even when it was "up" it could be down. Lots of mysterious glitches and weirdness, stomping, restarts. Not 100% sure it was their fault. But didn't see any definite evidence it was ours either. In comparison, WebFaction and Linode have been great. Though I settled on Linode for all new projects for several reasons that I felt made them better in the general case.

Oh, but I've had all sorts of other fun failures with dreamhost in the early days. A number of us regularly called it "dreamhose". It seems to have matured, and I keep some material on there, but I'm still wary of putting anything mission critical on it.