I have found Dreamhost's support to be beyond excellent in quality, often very prompt, usually plenty timely) sometimes a little slow (rare, but sometimes!). When it IS slow, it is more than made up for by the quality... the responses I get are always from people who seem to be genuinely <em>dedicated</em> to dealing with my issue, with no blowoffs or prolongings (asking unnecessary questions to delay having to actually do anything).
Often, on any deeper issues, the support rep with take ownership of the issue and all back and forth will be with that one person until the issue is completely taken care of.
I also enjoy the sometimes laid back, organic, truly human vibe behind the responses... I like being able to communicate with regular folk and not corporate drones trying to maintain a facade of pseudo-professionalism.
And though it may seem a small thing on the surface, I REALLY appreciate the closings such as:
"thanks again for reporting and if you every find any other issues let us know!"
"If you have any other questions or would like more information just let me know!"
"If you have any other questions or need anything else, just write back and let me know! I'm here to help."
"If there is anything more we can help you with, please let us know and we will be more than happy to accommodate!"
And so far it looks like they mean it... they have gone to far more trouble accommodating me than any other host ever has, and more than most ANY type of business has.
The longer I stay with Dreamhost (even through the rough times) the more I am pleased with the overall experience I am having, with anything that's less than perfect being well balanced out by many things that are beyond awesome.