I purchased a package of nock's and inserts a while back just to see what they would do as far as arrow flight and grouping. Wow, they decreased my groups by half. I'm not a great shooter, but to go from 4 inches to 2 inches at 20 yards is a big difference for me. This was with ICS Bow Hunter 400 shafts. The ICS Hunter shafts come with Vibrake inserts and nock's, I always wondered if the inserts and nock's made a difference? Much to my amazement it is a big difference. I would not give these a 5, give them more like a 10. Perfection!!!
How much difference could a nock make? More than you think. These nocks definitely made my shots more silent. The grouping improved at distances 30 yds. and longer. They are easy to install and affordable.