We built OTA sync using Google App Engine for Appigo. Check out https://appigotodo.appspot.com https://appigotodo.appspot.com for more info. We have sync'd mill

We built OTA sync using Google App Engine for Appigo. Check out https://appigotodo.appspot.com https://appigotodo.appspot.com for more info. We have sync'd millions of tasks since our launch in October. It wasn't a trivial development task, but it definitely didn't take us 2 years. There is a fundamental difference in the way CC is approaching sync. They are trying to sync by moving the actual database around instead of using a protocol based service. They must have some reason for why they need to move the actual database file around but I don't know what that is.