Actually I use Fastmail, and am a big fan. I've never had an issue reaching support. Of course I've rarely had to, the service is pretty reliable.

As for features, I could flip that around on Gmail. Does Google rigidly adhere to imap/carddav/caldav standards so that standards-compliant clients have no problems whatsoever in connecting, or are there still cheerful little "quirks" when trying to use non-official clients with Gmail?