I'm hoping that the entire paintball community is wrong and that schecter has revolutionized the way we look at barrel length. You should get Mike from techpb to do a video about barrels. Maybe he already has, I haven't looked through them all.
I'd really like to see the results of that engineering final. I think if it really took all factors into consideration that it would have found that paint to bore match and the quality of paint would make a much greater difference than a few inches of barrel.
If he used different barrels that would have different manufacturing specs and different bores, it would totally destroy the idea of comparing lengths. ie; the stock barrel from a spyder is 10" spyder barrel, and if I compared that to a 12" J&J ceramic, there would probably be a huge increase in accuracy. In your mind you attribute that to the extra two inches, while everyone else realizes that it is simply a higher quality barrel.