Didn't really want a hacked one, as I've heard of people having problems like you say. As long as the phone is out of contract then there is no problem unlocking/hacking it, but during the contract period the phone still belongs to the provider, hence the high monthly contract payments, it's just credit to buy the phone. So got to be careful buying unlocked "new" ones.
When I lived in Spain for a while, their contracts work very differently, you pay virtually full price for a phone, i paid 400euros for a decent one back then, and the contract was 9euros a month minimum charge. I think a lot of places around the world work like this, it's only us who are in love with credit :roll:
Anyway, i'll do a little more research into these unlocked ones.