Might just be a coincidence or me just being new to the direct Exchange sync but it did seem more instant yesterday.
That said, even after redoing the Server (deleted and re-added) it's still slower.
I guess I'll leave the hack implemented
UPDATE:
I was getting spoiled... turns out it was only when the status of a message changed from one or the other. New items and outgoing emails update almost instantly. But the status of read or deleted doesn't change until the next sync.