We have moved our sites to a better server. Migrating to an un-managed private server is quite an experience, but you get to play with Linux distro of your choice and learn a lot in the process. Plus, you get freedom, root access, and can make partitions, clone the system, can build OS & webserver of your choice from scratch. Although WordPress doesnt need a lot of freedom or root access, simple LAMP stack with mod_rewrite enabled apache would be adequate. I chose Ubuntu Server 12.04 LTS & Apache 2.2. I must admit that complexity or freedom was not the reason for this move. I’ve few complex wordpress sites running with multisite or buddypress/bbpress setup; & they’ve been running without trouble on shared hosting.
You should see significant performance improvement on our sites network now. I have been thinking of Amazon web services (AWS) & MediaTemple’s (+ve) hosting for couple of years. But then I found a better service & suitable servers. Name is Linode. Their servers are located all across the US, one in the UK & one in Japan. You get a choice of 6 locations & build your own CDN, setup load-balancing & make a highly scalable setup. You can increase RAM, disc space with a click of a button & get charged on a hourly basis. They’ve been doing cloud before cloud 😉 enough said.