Sometimes taking the time to range a deer and then adjust the sight is a good thing. It slows everything down for me, and makes me "think" things through instead of moving to quickly and making a stupid mistake of some sort.
I've shot two antelope in the last three years, one at 58 yards and one at 43 yards and in both situations, it was spot and stalk and in both situations ranging the animal, adjusting my sights yardage, and then taking the shot went very smoothly.
Last years whitetail buck and last years turkey, same thing. Ranged the animals and never felt "rushed" on the shot. Actually, in all shots on game, at the moment of truth, I feel VERY confident when I release the arrow.
For me, it helps to add the step of adjusting my yardage. I also agree with meanV, having the one pin set exactly at the yardage that you're shooting jsut gives confidence at the moment of the shot.