I bought the M*Carbo Beretta 92 spring kit from my friends at Calgary Shooting Centre. You can watch the in-depth video of how to install it at the M*Carbo website, it is a bit involved. But, yes it works exactly as described. My 92 went from an 11-pound double-action pull to a frighteningly light 6.75 pounds. The single-action pull went from 4.75 pounds down to 2.5. I have had one misfire out of 800 rounds of reloaded ammo using Ginex primers, which then fired on the second strike. I have decided to continue testing and if I get another misfire -- even using Ginex -- I will switch to the next heaviest spring. Right off the bat, I installed the lightest springs of the selection that come in the kit.
The Beretta 92FS is a very accurate pistol out of the box, and I am most pleased with mine. I shoot PPC courses with mine, just by myself, practicing for when the wife and I return to Mexico. The PPC/Modified is a very popular course in the Mexican clubs, and the Beretta 92FS is a pistol that can be obtained and registered with a bit of "manipulation" of your local authorities.
I look forward to a restoration of our rights to buy handguns in Canada when Pierre gets in (and if he doesn't come through, well, there's always Mexico isn't there?) so I can send my 92FS off for some cerakoting* -- because if it gets "lost in the mail" right now, it is not replaceable. And that would suck. Watch the M*Carbo video, and trust me, they are not lying to you. The results are that good.
Cheers!
*I am thinking of an O.D. Green frame and a Flat Dark Earth barrel with the slide assembly in original blue.