I just wanted to add my support for this as well. Just had a very complicated move due to poor response from my old host and the Nimbus team were fantastic. As someone else said, yes they are a little bit more than others, but so far I can say with confidence the support you get in return is well worth the extra money. I have never had an account manager personally call me during a migration before to keep me updated, but Matt Cooper did that which was a great personal touch.
Raised my first ticket last night for just a query, had a very helpful and personable response this morning (non critical query so response time was fine).
Pretty impressed so far.