I've played around a bit with autotune on my home rec rig-up. I use a freeware plugin (can't be arsed to look up the name of it right now, sorry) but I feel compelled to point out that the thing is ADJUJSTABLE.
It's not all-or nothing, like a switch with two positions -- Dylan or Cher.
The one I use has parameters for attack time, tolerance of off-pitch-ness (not what it's called in the manual), amount and speed of correcting. You can get the weird glissando effect or something much more subtle. And you can program it to shift in and out, not always be active full-time.
Possibly more interesting, it also has choices for various temperaments, and a way to set custom ones (if I ever figure out how to work that bit of it).
If you are only shifting a flattish note up a few cents, it works reasonably well. More than that and it's definitely un-subtle. The rationale for using it to fix a recording is that, like a mistake in a wallpapered room, you'll notice the blasted spot every day hereafter for ever and ever amen, at least until you change the wallpaper.
But in the end I find that the amount of effort needed to get the correction just right without the ugly side effects is more work than just punching in a fix or retaking the whole track.
And I wouldn't be caught dead using the live equivalent, even if I could afford one. It's bogus for anybody IMO, but especially wrong for someone like me whose musical sound has been described as "well lived-in."
-Glenn