I think this is a cool thing to have. I usually archery hunt with a crossbow and I only recently found a crossbow mount on Ebay. My son is 13 and will hunt with me this year and I think that having the right range without trying to use a traditional rangefinder or using landmarks to try to remember different ranges will be a big advantage for him.
Pros: seems to be accurate, one less thing to do while staying still
Cons: a little expensive
This review was written in the old system and had content requirements that are different than reviews written today.