To me, straightness is fairly important, but spine matching is even more important. I have a very accurate spine tester, and when it comes to fixed blade broadheads I'd rather have .005" runout and consistent spine across my arrows vs. .002" straightness and big variances in spine.

And not only spine differences from shaft to shaft, but spine differences WITHIN the arrow itself- like having stiff or weak sides of the shaft.

As the energy of the bow is being transfered to the arrow shaft on the shot, spine variances will affect how that arrow leaves the bow- slight changes in how it bends and how it reacts to the energy put to it. The differences in how that shaft reacts from spine variances equate to erratic (or poorer) broadhead flight.

Going through different manufacturers arrows can be eye-opening as far as spine consistency.

Ever notice they advertise specifications for straightness and/or weight, but not for spine tolerances?