I use it loads in the studio. I'd rather get a powerful performance and tweak a couple of notes afterwards than try and drop in a word or two, as that always sounds unnatural to me
It's a bit frustrating when people want that "perfect" modern vocal sound. If you've heard any country song made in the last 5 years you'll know what I mean. I have one guy who comes to me, a truly incredible singer, he's never out of tune, but he wants that sound. I have to go through straightening out any natural wobbles or unintended vibrato and it really sucks the life out of the performance.
When it's used for effect it can be pretty cool, although that does seem a bit overdone in some of the recent rap tracks I've heard