I recently migrated all my domains to fastmail (left my legacy gapps account as is, just in case) and am super happy with it. I am using a regular google account on the side for all the googley things I need but haven't opened gmail ever since.

The only thing I miss are labels. Once you get used to how to use them, it's hard to go back. I migrated my mailing rules to use folders but that forces me to check every folder for a new mail and don't have it aggregated in my normal inbox.