Re-itterating Double Creeks comments about durability, carbons will far outlast aluminum if shot the same amount. I purchased 1dz. XX75's back in '96 whaen I purchased my last bow. These arrows lasted 2 years or so before the majority of them were bent. I then purchased 1 dz Beman Carbon Hunters in '98 and am still using 8 of themtoday.This is the main reason that I will usecarbon and if I could find more of those old bemans I would buy them in a heatbeat. As far as tolerances go you can only get so close to perfect.