When checking my 4S on here is was very accurate. I had checked mine about an hour before I received my email from unlock_fusion and my 4S was still locked. As soon as I got the email that it was unlocked, I checked again on that site and it said it was unlocked.
I had the exact same experience.
As for some AT&T users reporting that they got their iPhone 5's unlocked to begin with, there have been posts on this site saying the same thing. I'm curious whether those reporting that their phones came unlocked purchased their iPhone 5 from AT&T or Apple?