I believe both points have merit. Hugh's point about real world testing is right on. However, Loco's point about conditions not being identical have some creedance as well. That is why I was reluctant to post, and only did so with some coaxing.
But consider this loco. Conditions were not identical, however, they were very similar. Now, if i had only gained 1mph on the gun, i would have said it was too close to call for a non same day comparison. However, the gain was too great, and could not have been from a slight advantage from the conditions. 3MPH is a BIG DEAL on this hill guy