i think you wouldn't say its faster. going in depth on what frummer said. for powerglide, the initial step on the pedal causes it to 'fly' towards the head with more FORCE then what is applied. Think physics. think moments. less strength for more power. as the beater passes the axle perpendicular to the floor, it increases its velocity very quickly. this is due to the shape off the cam which is uh...not uniformly round.....yea... less force reduction before the beater reaches full strength.
the rollingglide however has turning action which is proportionate to the amount of force you put in. meaning that it has a very uniform feel. on the movement.think Force directly proportionate to the energy you put into the kick. this is due to the uniform round cam. i guess another way to put it is it feels more natural. Hope this helps.