This whole 'superlight' thing has really piqued my interest. My current go-to is 88g wet - the lightest racket I've ever owned - and when I go back to my other rackets (90-93g), I reckon I get maybe a >10% power boost that gradually tapers off as I get more tired.
Thing is, I don't have a big smash. If I smash, I win the point through placement or angle, not power. So the arguement would go, that if I could speed the rest of my game up and not to the detriment of my power game (which I use less and less these days) or my shoulder for that matter, then that would be a positive thing.
Is anyone having any physical issues with the FB? You'd have to swing your arm/wrist faster as a matter-of-course, so before I'd contemplate going down that route, I'd have to get a better handle on the potential for injury.
I agree with the rest of the comments. The FB doesn't make me sore at all even after 2-3 hours of continuous derbies. I really feel that the modern game rewards players with accuracy, more than power. The only adjustment that's worth noting I feel is in the racket handle control. With such a light racket you should take advantage and use finger control and leave a gap between the racket handle and your palm. With such a light racket it's possible and you won't get palm stiffness.