The newer breed of fast short bows are putting the arrows out there incredibly fast. They also need to shoot much stiffer arrows as a result. What this does is allow you to shoot flatter so you get more yardage.
My dad got a real taste of this once while filming for the Outdoor Channel. He shoots a recurve, with Cedar arrows. The rest of the group was shooting the high dollar fast bows, and he said these guys could shoot groups all day out to 80 with no trouble. Funny thing is that they were impressed with him since he was doing it natural without all the scopes and such. I forget what he said the fps was for those arrows, but I believe it was twice what a recurve did.
FWIW, I shoot a Longbow.