Both are going to probably be great. Proof is obviously the most well known, they make a great product, and to boot they look cool. However, it seems like we're on the precipice of the next generation of carbon fiber barrel technology being released that has the potential to do more than just lighten things up and look cool. Hells Canyon seems to be in this group. So are the Paradigm Carbon barrels and the barrels to be released by Straight Jacket Armory. The newer designs are stiffer and the carbon is actually utilized in a way to maintain barrel straightness as the barrel heats up, instead of simply as a means to replace steel to lighten things up. When combined with a world class barrel blank they have the potential to truly allow for maintenance of extreme accuracy over prolonged strings of fire...like 1/2 MOA 20-50 round groups.