No matter what you decide, if you're shooting carbon arrows, be sure to nock tune your bare shafts before you do anything. It is somewhat tedious but you will be extremely thankful in the long run. My big takeaway from going to EFOC, via a heavier arrow up front (from 373grains to 532grains) with foc of over 21% is that most of these carbons fly great on the spine but off the spine, you'll be pulling your hair out thinking its your form or the tune of your bow. Trust me. Trust me. Trust me. If you don't have bare shafts, or don't feel like stripping the fletchings off all of your arrows, paper tune each fletched arrow at 7 yards by FIRST adjusting your nocks on each arrow a quarter turn until you get small tears or ideally bullet hole tears. Just try to get the smallest tears possible by rotating the nocks a quarter turn and shooting through paper for each fletched arrow until you get super small tears. Then, start your tuning process. Obviously, this is assuming you have a drop away rest which doesn't matter the orientation of your fletches on the arrow. Or get Zingers and be done with it!!