Maybe I'm the only guy that ever had problems using arrows too stiff that I left long.
What I notice about them, even when they spine right, is that when you bareshaft at longer yardages (or through paper) long arrows will always fly much more tail high than arrows that are the same dynamic spine that come close to the front of the riser. It doesn't make sense, but through my own testing, I've found it to be true.
one other thing I do...
When I bareshaft, I add the same tailweight that whatever my fletching would be, in masking tape.