I really like my P11 except the trigger. See the Mcarbo trigger system ads, curious if anyone has actually tried it? If it works would make the P11 about perfect for carry.

Have bought several MCarbo products, some spring kits for other pistols and rifles, and have been very satisfied.  No experience with the spring kit for the P11.

I had mine installed at Kel Tec and it's made all the difference, a really great upgrade.

I bought this kit and did the install hoping that this would clear up a trigger reset issue that my gun developed.  

Mcarbo sent me a video link after I bought the kit that walks you through the install. Following that and taking my time this wasn't too bad. You'll need a clean workbench, a punch block, a set of punches, a screwdriver or two, and some patience.  

I can tell you that it takes a little while for the trigger spring to break in once you do the install so if you get done and it still feels heavy don't lose heart.  The press weight is reduced to something more like 7 lbs, the smoothness of the pull is increased, and overall I'm happy with it.   My only caution at this point is not to go too far with the over travel stops.  The trigger reset issue went from once a mag to every shot when I first installed this, and I think that its because I had the overtravel stops backed too far out.   I've removed them entirely for try #2.  I'll let you know if that clears things up, but it looks like my gun is one of the rare ones that has this reset issue.   Reading around on the forums I don't see that for other folks.

I've never used Mcarbo products in any Kel Tec but have used their trigger springs and other items in multiple Rugers I own.  I have always been happy with the results from Mcarbo and don't see why using their stuff in a KT would be any different.  My Ruger LCP's trigger is a world of difference better with Mcarbo's spring kit and that gun is a rip off copy of the KT P3at.  Mcarbo is a pretty stand up company in my opinion.

I've used mcarbo for Savage axis and world of difference. Not match trigger but easily 100x better. Took a buck with that gun this year

Good company with good products. The "Brotherhood" thing is a bit cheesy IMO but I'd have no issue buying mcarbo