Written on: 23/05/2012
The official iPhone unlock is very expensive, and I'd wager it can be bought a lot cheaper both online and on the High Street. However, they claim that this is due the assurance of their service, which I can sort of believe given the unreliability of some retailers I've encountered in the past.
They told me it would be 48 hours before the phone was unlocked, but was maybe 60 or so. This was mildly irritating, but they were responsive to emails and were courteous and informative.
Overall, I'd recommend them. Just be careful to order the official unlock rather than the cheaper versions, as the latter are powered by jailbreaks which (a) can be obtained for free, (b) invalidate your warranty and (c) restore locks when you update iOS (though to be fair, in the case of the latter, they seem to give comprehensive advice and support surrounding updates).