The benefits of quick fire are that it gives you higher burst attack speed for shorter periods. People mainly prefer it for oly for obvious reasons. It can also be enchanted for +p. def which some people like, but IMO the p.def bonus is negligible. Personally I think keeping rapid shot is the way to go, because I hate short duration buffs and I'm not an oly warrior.
Also the "max" attack speed is not really the max. You can shoot skills faster even going above 1500 attack speed.