I' ve seen the argument that spine consistencey is the more crucial of the two factors (spine and straightness) and I would tend to beleive this. I think I could tell the difference shooting arrows that vary in significantly in spine more than some that vary from .001" to .003" in straightness.

I don' t think the manufactures offer a value for the amount of spine variation that is acceptable.

I just shoot the Gold Tip XT' s and I' m afraid they probably shoot way better than I do. I' m going to have to try the Carbon Express' that archerick mentioned though. Even thogh they are said to be more fragile than the GT' s.

-Chief