I'd bet the house that there is a difference. that deal hm is talking about is more proof and what he said is correct. its the same deal as a rifle just more exaggerated because of the arch, slower speeds and they don't shoot as flat. its called "angle of departure" i've got computer programs that will work out the difference for you and there are mathematical equations that prove it to be true. you are right at 15 yards its not going to show that much difference BUT it is different. if you get a range finder with the arc system, thats what busnell calls it, or whatever the manufacture calls the system, you will see that it is true. you can argue with me but you can't argue with physics. but hey if your system works for you go with it. i got an idea lets pose the question to mathews or PSE, the real best bow ever grin, and see what they say. ralph and vicky, lee and tiff, mike waddel, the nudge, david blanton, manufactures like bushnell and leupold, all say the same thing i'm saying. are they all wrong as well? again you shoot your way, and a honest good luck to you, and the rest of the bow shooters world will shoot theirs.