For shooters with 26-28" of draw length using bow lengths of 66-68" I have found that through a speed trap, the arrows out of similar weight but different lengths shoot very very similar in terms of fps. I used to shoot a 75#@28" Big 5, that was 68" . Running out of leverage during the draw, I pulled it 26.5" all the time. It shot 180fps with fast flight and 500g shafts. I had a 66" 50#@28 W.Special that even when over drawn by me to 28" would only kiss 158fps. What I am realizing is that even though I drop down considerably in draw weight and "can" draw 29.5", I don't shoot a bow like that for very long, I'll get in to a groove and "just shoot." When that happens, and as an athlete I will tell you it ain't cause I'm tired, 26.5" draw and accuracy is the result. Just letting natural reaction dictate what is needed for the shot scenario at hand, 26.5" no matter the draw weight, bow length, gpp, foc, etc..
The only thing I have ever noticed is that when directly comparing bows long and short, is that once that string angle has approached 90deg you have gone to far. Getting the string angle to be appropriate to your draw length, regardless of bow length, is a big part of this system.
Do you think Howard's heavy bow pulled 2-3# per inch in the last few inches of draw?? I doubt it on an 115#'er more like 5-7# per inch. Was it stacking? was it "smooth?" Nope, how else would you fit 115# of tension within 22" of power-stroke? I seriously doubt there was much, or ANY for that matter, "preload" in a string-follow wood bow.
Man, looking at my 500g arrows come off 47# makes me want to go back to 70#. I know, I know, not needed, overkill, you'll get hurt, but wait a second, you mean to tell me that a 500g cedar coming out at 150fps is gonna blow through the brisket on a frontal shot, of a relaxed, looking the other way, rut minded, 220#er, 10 point?? I know for a fact that 705g tuned efoc carbons will not penetrate a 300# shielded hog from close range, no matter how many times you try to, it ends up looking like a pincushion, your better off with a spear anyway with big hogs.
I want no surprise's, no nonsense, reliable, boringly so, set-up that I can count on for the hunting shot that I wait all year for. Not me running through the woods tracking the thing down with "follow ups." Is that 150fps for you? or is 180 a little more confidence inspiring??