I have a 6 x 20 Leupold.
I set the Parallax at appx. 175 yards when big game hunting and 100 yards when coyote hunting.
Then I don't ever have to mess with it while hunting.
I have never missed an animal due to parallax problems or it being too out of focus due to the parallax setting or having to fool with my scope parallax settings while hunting.
It would have to be at extreme range before the animal would be too out of focus to take the shot with the setting set at 150.
Only time I actually set it at the exact yardage is at the range.
