I know that MediaTemple is very cozy with the design community. Other than that, I can't glean much from their web site that would separate them from other hosting providers. I am curious for any insight on this as well!
After taking a look at them, the only thing I could find that set them apart was cost... They're _much_ more expensive...
That's all I've figured out myself. Too bad no MediaTemple users have commented ... I'd honestly like to know what keeps people using them at their price!
I think they tend to pride themselves on their service (which is pretty good I guess.. the tech people you talk to at least seem to know what they're talking about), and they emphasize their scalability. I'm not sure if those things justify the price, but I guess some people think so.