Tried to sync this afternoon and got "There was an error syncing with Garmin Connect" (the error was "Unknown error" -- helpful).
Tried a couple more times, got an update notification. Installed the update, same problem.
Deleted the Garmin Express app and reinstalled from download. Same problem.
Deleted my 620 from Garmin Express and re-added it. Now Garmin Connect website has a "Congratulations on your new Forerunner 620" (thanks, I guess) but still can't sync, same error.
I *really* wish they would figure out the update stuff because I need to go through this uninstall/reinstall loop pretty much every update and it's annoying as hell. I thought Garmin was a premium brand?