I am VERY pleased to report that the international unlock (the request through Sprint went very smoothly) successfully fully unlocked our 4S. In fact, that phone was already on AT&T using one of those sim interface chips that can be found around the net; we just inserted the AT&T sim directly, waited until the phone said "Activation required," entered the iCloud password and that was it! It was a big relief since we thought that we will never see that phone unlocked.