I just ran some numbers through my Archers Advantage program and my hunting bow can hit the 12 ring at 40 yards from 39.1 to 40.8 yards.I increased the speed by 20 fps and I can hit the same 12 ring at 40 from 39 to 40.9 yards.
This is how it really works,the key to winning is being able to execute great shots time after time.AND judging yardage is a must to win at the national level in the open classes.
That isn't saying that speed doesn't help.A 1/2" at 40 yards might be the difference in winning and losing BUT if you are misjudging by 3 yards,you probably aren't winning anyway.[8D]
What Matt has experienced is pretty normal,he said he makes stronger shots when he doesn't know the yardage resulting in better scores over his known distance courses.Most will blame bad yardage before they will blaim themselves for a bad shot.Others have more confidence and make stronger shots when they know the yardage.It boils down to having to be able to shoot AND judge yardage to win.If you are counting on speed to carry yards,you probably aren't in the running anyway.
It is funny how this discussion keeps coming up and someone has to go test it and come back saying my info is correct.When doing the testing,just make sure the bow is tuned and sighted in for the slower speeds and document the drop from 1 speed to the other within the normal 3-d ranges.
BUT,the bow in question on this thread is a little more than 20 fps faster than the ASA maximum,there will definately be some yardage estimation adjustment to be made.Before I would slow a speed bow down,I would setup a target bow for it's intended purpose at the desired speed.