+3 hate long sanding jobs , Lonnie for me chronys can be touchy some times location ,lighting etc , as you probably know ,but with mine I found shooting at least 2 arrow lengths away I get better results & right spined arrows , I don't know how much gain switching to fast flight will get you on glass bows, I just started making them but with natural material bows I can get 7-12 fps gain using FF over B50 , depends on bow and string count , I also found with that design you made playing with the brace height made a difference in speed , I should do some test on mine only pulling it to 28'' vs 30 1/2''.