Which heaven forbid you try syncing anything other than Mail. Contacts and Calendars have some very subtle bugs which snowball over time (and even on Google Premier Apps).
Google Contacts also uses a different set of field names, and will frequently sync "main" to "other", for instance. Or just mess up field formatting, or break gtalk ids...
As soon as iCloud was released, I happily ported over my contacts. It's been a much better experience so far (I can finally use large contact photos!).