Howdy troops - here's my take on the issues of "power" (yes, issues plural) among racquets with different heft and flex. Just my perspective though...
I grew up playing serve & volley tennis, so this gave me a keen appreciation for a frame with some stability around the net along with a nice measure of "pop" to put some authority behind both my volleys and serves. My ProStaff 6.1 Classics were wonderful for that sort of work and they also had enough head-light balance to be rather maneuverable for me.
When I started spending more time around the baseline, those 6.1 Classics forced me to reign in my strokes enough to keep the ball down on the court, but eventually I tried out some more flexible alternatives, including the LM Radical mp, Prince NXG, and Volkl C10 Pro. The response or liveliness of these softer frames was generally more mellow for me, but that meant that I found a greater sense of control and consistency with the flexible racquets - I no longer needed to hold back like I did with the 6.1's.
So while a stiffer frame may seem to "have" more power in the form of that extra zip off the string bed, my softer racquets let me play with more power. I can take significantly bigger rips at the ball with my C10's and still keep it in the court. I should note that I've tried a couple racquets that seemed just too soft and lifeless for me despite their weight, but I've also sampled a couple of stiff frames that felt under-powered for me because they had no weight to them.
In Lee's defense, I think that this individual fit is tough to nail down just because swing speeds and styles vary a lot out there. The optimum racquet response for each of us will boil down to a somewhat unique recipe that includes the weight, flex, and also string type and tension. Numbers aside, there's also the ultra-subjective issue of feel. Our racquets need to tell us what's happening at contact so that we can distinguish between good and bad shots. Here's to good vibrations, right?