I'm currently shooting the 5575s, but do not feel qualified to answer your spine question. I can get a bullet through paper, but have never paper tuned at various yardages, usually only 4-5 feet away or so, the 5575s are two years old and the hunter grade, so the spine and tolerance are probably all over to begin with. As long as I could hold a huntable group I was happy. Now it's no longer good enough.

I went with a drop away to negate the spine issue, but for supreme accuracy, now I know I still need to pay close attention to it. I ultimately want my set up to go right where I aim it, time after time, from arrow to arrow. If it doesn't, I want to know I was the weak link, not my equipment. To me it's all about eliminating variables. Hopefully the ACCs sporting Magnocks will do this for me. Time will tell, and then so will I

Thanks for all your help