Basically, the only way I got it working alright was through Nuevasync (I Bought a pro account - wasn't that expensive). They act as a gateway between you and Google (which means you have to give them your google password).

You can't get Google calendar + contacts sync over 3g any other way, it seems.

Now if you are happy with just mail, then it's a whole new story... Go ahead and use POP, IMAP, ...