I had 80%, and on my new bow got 65%

I think its one of those preference things, manufacturers say that high letoff allows you to hold longer, which I agree, but where they different on archers/manufacturers is they claim higher left off allows you to shoot more accurately, and Ive heard/read from some pros they prefer lower let off, ie theyre holding more weight, they claim holding more weight keeps them more stable/tight if you will, where as lower weight does the opposite.

This is one reason I went with 65%, the other, imagine your arrow going from 12lbs to 70lbs.....vs......20lbsto 70lbs, in my own head I see that is a greater change in froce applied to the arrow, to me a smoother release of that stored energy would allow for better arrow flight and accuracy. I haven't read about this, its my own theory, maybe someone else has written or studied it, I'm unsure, but for the above two reasons I went with 65%, oh and the record books put an * next to your name for 80% let off. Not a big deal to me, but for some perhaps.

Oh and Idaho requires 65% let off, wont allow 80%, less theyve changed things, though I doubt anyone would bust you for an 80% there, but who knows, you may want to keep legal!