The less yardage the better. The farthest I've ever shot anything under the perfect conditions above was a fairly large reindeer at 39. Given that I wouldn't like to shoot whitetails at anything over 30 and 100% of mine have been under 20.

I'm more impressed by someone who makes the killing shot at 5 yards than the one that does it at 50. (3-D is just the opposite but that's another game altogether...)