DreamPress is a supercharged, optimized for WordPress VPS from Dreamhost. We run geistinteractive.com and modularfilemaker.org on it. It uses Varnish and Memcached to keep WordPress just zipping along. Overall I’d say we are pretty happy with it. But when you are developing your site, the aggressive caching can really throw you. I have sent a lot time yelling at the browser, trying to figure out why something wasn’t showing up as it should. I finally figured out a good way to deal with it.