It's not really an issue with the hosting. There are a few things that are different with Dream Host vs. GoDaddy, but we had problems there too, remember? Really the problem is us, generally speaking. Me, more specifically.
I've tried to balance cost vs. performance (hey, it's a VR-4 site). Now that the coffers are replenished I've upped the plan a bit (performance) and we've got 500MB of RAM to utilize nowv (as in just now). I did recently discover that Dream Host forces compression on the pages and we were compressing the pages ourselves. Unfortunately that requires some processing power that was above our pay grade. When we go over on our plan they automatically restart (our virtual) server, this causes lags.
There's a few more tricks that GoDaddy had that DreamHost does not (by default) and I'll be testing these out when possible.
Overall the "hosting" part of things is really fast, but the database is not so much -- and that's really an issue with the design of this software. Always has been, but that's why it was kept so lean (post retention). We've slowly upped the sizes of things and we've really hit the limit of the performance without making some changes.
Change is coming and the last round of donations was spectacular. Just keep bearing with us.