I've bought The Missing Sync for iPhone some months ago. Now with the update to 1.0.2 it's the first time (!) it works for me.

BUT: While I understand that Apple's API doesn't allow two way syncing so far nevertheless there would have been a lot of room for improvement which could have be done already in the past from the Missing Sync's manufacturer MarkSpace. Unfortunately they missed it and so Missing Sync for iPhone is still a very rudimentary solution even mostly without standard features like e.g. sorting dates up or down in SMS Log, showing your contact in sent SMS in SMS Log etc.

So I think it's still highly overpriced and therefore not recommendable at all !