Spinning them before you go home doesn't really prove much when it comes to carbons in my opinion. It seems that the majority of the issues with carbons are at the end (usually nock end) and most places do not cut anything off of the nock end when they cut to length for a customer. If the straightness is off the entire shaft that's less of an issue.

Almost all of my arrows come out good after spinning to see which end is worse and cutting more off the bad end. I care less about my logos aligning than my arrows spinning true. I just cut some arrows for a friend that had 2 that still wobbled after cutting. He fletched them and says they now spin true. Even the ones that don't are great for practice. Even Len agrees with that.