ScuL:
Amazon have got a global return policy so it shouldn't be a problem, factory repairs are still directed towards local repair centres. The local one for NZ is in Newmarket which is 15 minutes away, I've had my Z1 repaired there before and received excellent service. Just despise telco branded phones, so quite pleased with a non-branded one :)
I've never had one: my iPhones all came direct from Vodafone and had no logos on at all. Didn't know it was a 'thing'!