Just an update--I have been shooting these four arrows for a bit now, and while I still miss plenty, I also have hit some really nice groups on a far more consistent basis than ever before. I am now confident that when I miss, it is my fault and not the equipment. It is also nice to see just the nock and the spinning fletchings going down range.
Of course the down side is now I am getting a soft spot in the middle of my target and since the arrows are flying straight, they sometimes penetrate up to the fletchings. . .
DC, I have noticed the same thing about bamboo thickness and spine.