ORIGINAL: GregH
Last I knew, most of the big name 3-d orgs,except IBO, were all using a speed limit. 280 fps + or - 3% = 288fps. It was designed to allow the short draw length archers to compete with the long draw guys. Not sure if this has changed. Usually along with increased speed comes some negatives. Noise, vibration and excessive wear and tear on parts.
As far as I know, ASA and IBO are the only major 3D groups, NFAA/NAA and Reading Trail shoot all host them, but they are marked yardage where speed isn't nearly as important. IBO does have a limit, just a different one than ASA. The problem is there is little difference in drop from 280-300 when you restrict the distance of the shot. There is some, but its minimal. The guys who win the big shoots shoot 280 in both events. You can't equalize totally, a longer draw shooter will shoot a fatter arrow at lower draw weight to stay at 280 so he still has an advantage.
Back to the topic, you can play with the cam to make it faster, but in general the faster you make the cam by building to peak weight faster and lower let-off or VERY narrow valley, this makes the bow less pleasant to draw, hold and shoot.
Also the higher speeds, I feel, are beating on the targets and we are blowing through targets faster and faster than in the past.