I had multiple servers with Slicehost for over a year before I heard about Linode in a VPS comparison. I migrated one of my WordPress servers over, and by the end of the month had moved the rest of my web, email and database servers over.

Don't forget to look into their StackScripts and Library to make your life even easier. I've installed LAMP and LEMP so many times now that the StackScripts are of no benefit to me, but I did make use of their Postfix/Courier guide in the Library - Never been able to get IMAP working before that, and it's been a life saver when I'm on the road.