ORIGINAL: HuntingBry
You make a good point in that you shouldn't rely on only one method to determine if your bow is tuned. If you check everything over and use seveal methods, broadheads and field points should be close to, if not the same in flight. If they are not, it's more likely and arrow problem than a tuning problem.
My original post was too long winded, but that's what I was trying to convey