Back in July I looked at moving web hosts to Dreamhost as they got high marks on several Drupal related boards. Indeed they have a lot of great ideas. Ultimately two problems caused me to invoke the 97-day money-back guarantee.
The first problem reared it's head as I started to transition domains to Dreamhost. If one has a "fully hosted" domain with Dreamhost they presume that you will have your "www." name pointed to their www server. Therefore it's not possible to have their DNS setup without having www.example.com pointed at their server. This makes for tough going when one wants to test and transition.
Fatally, however, the email system for IMAP was terribly unreliable. Time after time it would ask for my password when it had just been given. Perhaps it's a client issue or a conflict between the client and server but whatever the root cause it proved fatal for their hosting. It does seem that POP clients worked reasonably well.
Dreamhost's MySQL, PHP and therefore Drupal support earn high marks. It would be great if they'd add it as a goodie to install in their hosting control but it works pretty well otherwise.