Well, let's definitely point out that to get good ADR you need: a good mic, a good pre, a good room/stage, a mixer who knows what they're doing, an editor who can cut, a re-recording mixer who can mix, and oh yeah: an actor who can loop!
Seriously, put an actor on the best ADR stage in the world, and if they can't get the feel/vibe/character that they had on the set back, the director's going to say "Yeah, I think we'll just go with production on that one".
All things important
