I've been pretty content with Fastmail. I use DAV5x to sync calendar, contacts, and tasks to the system data store and is available just if it was coming from the Google services. I can even setup the DAV5x source as an account in the Google Contacts and Calendar apps. I wish Fastmail would have separate apps instead of the single integrated one, though. And the calendar could stand to gain Maps integration. And I've replaced Google Tasks with Tasks.org.