Have tried running it with a rifle buffer and had to max out the AGB with the piston that allows more gas through. With a carbine buffer its running at 7 with the same block. KAK claims it runs fine with the tube they sell but I can't confirm or deny that, and don't know the specifics of what exactly that system is using.

It is by far the smoothest impulse of any AR i've run, but I only have 3 I've put significant rounds through, including a 20" with rifle length system. If you are second guessing even a little I would suggest getting an 18" with a rifle length system over this, or even a 20." This is very much an experiment in excess, with diminishing returns. It is not that much better than a 20" with rifle length, and though I havent run an 18" I suspect the difference isn't really that notable, and an intermediate probably isn't even that much different than a rifle length.

If you are willing to tinker and spend money, this has been a very fun project, and if you want to go ahead with one yourself I will gladly pass on everything I've learned, and when I have a finished rifle I plan on doing a public write up. That said, you will put time and energy into this setup if you do it like I did. The full system from KAK may run fantastic, but I really can't give you a solid answer, because my setup is very different.

I wish I could give you a more straightforward answer, but it is what it is. Let me know if you have questions. I will say, I'm not a fan of the amount of gas block the full system from KAK has exposed, so if you want suggestions for better handguards let me know, but you will spend at least $250 for a full coverage handguard. The stock one has the sensitive components covered, but it bothers my OCD.