having read with interest the opions on this thread, i thought i would add my experiance(limited as it is).
i tried for years to swing from the ground up , with very inconistent results, and poor distance.
then i got the 3sk's book and had to effectly re-learn a swing, which is all about the late release of the club , ie an arms/wrist swing. at least that is how i am now swinging the club, and have increased distance and also slowed down the whole swing as well.i would say the maximum increase in my club head speed is down to wrists , releasing late and closing the face through the ball. very difficult to do and control , but worth the hours of practice , when it all goes right.i no longer think about my lower body , it just comes along for the ride, which has reduced my swing thoughts from a dozen to one. namely hit down and close the face. that in it's self is hard to do , as the timing has to be precise, but slowing the swing down a little helps, but if it speeds up , it all goes a bit pear shaped. i still think this is the way forward for me , and will continue this summer with this swing , and do battle with the speed demon and learn to contol what i think is a good swing.
hope this adds something to this thread.