Amy Lee is actually a decent singer, which is why the overuse of Auto-Tune is so pointless here. You can really hear it on the long notes, where they just seem to freeze in mid-air. It becomes very apparent in the chorus when the harmony comes in (0:52). Notice how the lower harmony sounds almost more like a synth than a voice – too clean, too perfect.
Now, I am anything but a purist. I have no qualms about using pitch-shifting when I need it. If a sung note in a long passage is a few cents low, I’ll reach in there and pull it up. I’m a better producer than a singer anyway. Auto-tune however, is a constant effect applied to everything sung – if it’s too high or too low, it pulls it into the center. It is also none too graceful with the portamento, which is why you will hear often hear passing notes jolt into the next, in perfect creepy harmony.
I’m not against Auto-Tune, I think it’s a brilliant piece of software and has it’s uses. I’ve toyed around with it and it’s pretty fun. Actually I recommend anyone who has a slight interest to mess around with the demo. It’s incredibly easy to use and will give you a better ear for hearing it in the wild, so to speak. I’m not against it as a tool, but misuse is incredibly apparent if you know what to listen for. Either use it delicately or go apeshit – like some of the R&B singers for whom it’s really an effect – ham-fisted use will render your music unlistenable in about ten years when the general public learns how to hear it.