i would think common sense would prevail here, but if you shoot an arrow through a whisker biscuit it would be slower, because it has constant contact causing drag. a drop away has no contact creating no drag hence faster speed. atleast thats what i thinkThe arrow is going across a rest as fast as the string pushes it regardless of the material or lack thereof it rides on. What the arrow does AFTER it leaves the string can/will affect speed.