I tried using their services, but since my sys admin skills are currently lacking (for Solaris) I just stayed with my current host MediaTemple. Mainly this was because MT's ui is ^$^@$#ing awesome. I could be wrong but I believe a YC alum is responsible for MT's admin UI. I've only seen one company compare to it and their prices aren't great
not to mention there are tons of tutorials that cater to their grid services... right now we're trying to just nail as many features as possible, so we're spendind as little time as possible doing sys admin work