Ambi controls? : for those shooters who are not right-handed or slice the pie around obstacles with the rifle in the left shoulder.
Those are the two most important points as to why.
The AR with standard controls has been used to slice the pie from both sides for well, over a half a century. Lefties have been using right handed gear since there was a distinction between the two. The only controls that need to be ambi are the safety(very nice to have) and the mag release.
The bolt catch is not necessary as using the charge handle works every time unlike the bolt catch. Regardless the bolt catch works for right and left handed users as is.
Why have ambi controls incorporated into the design? : so you don’t have a bunch of added on stuff that can snag on flora, equipment, etc.
I don't add anything to my rifles, they are stock with the exception of a BCM charge handle but that's nothing new as all AR's have a charge handle.
Why increase the bolt strength? : because bolt failure does happen. It is a known weak point in the AR design, and it can happen at the most inopportune time. If one can eliminate this weak point, it’s value is indispensable.
No doubt bolts break but replacing them regularly or at suggested intervals goes a long way. I personally have spare bolts, firing pins,
cam pins and cotter pins in the grips of all my AR's for such events.
Intermediate gas: a more reliable gas impulse that negates the requirement to overgas the gun, which happens to smooth out the impulse and reduce felt recoil. Why hasn’t KAC been copied? My guess is patent protection.
I'm onboard with the intermediate system but it never caught on which makes it proprietary and not on the desired list.
Tired argument? : I’m referring to the fact that there has been incremental change in the AR over its history. Some of it was decent, even if not seen on the first pass, and some of it was a clear case of two steps forward, three steps back, but in the long run we are better for it, and the platform has progressed.
I was there when the FN was ditched for the C7. I remember all of the #####ing and moaning about how our battle rifle was being replaced with a poodle shooter and a sproing gun (in reference to the main spring in the butt and how the shooter would hear the very tell tale noise from the spring upon firing). Scores went up surely, but these things couldn’t possibly be effective on a battlefield.
Next up was when we turned them in for the C7A1 and the ‘elcrap’. I blew a few qualification shoots with that ‘trusty’ bit of glass, and no one #####ed louder than I when that happened.
I can produce hits on target just as well with iron sights as I can with an optic. My scores went up with that optic marginally - bu5 only when it worked. You were a lucky and rare fellow to have escaped a failed Elian in those days.
But incrementally, they were improved and it turned into a bit of a dance : two steps forward, three steps back, and now four steps forward.
KAC is at the forefront of that change. Those incremental variations on the theme is what drives invention and betterment of the platform as a whole.
The incremental changes are excellent(for the most part) and to be expected with any design and any product. The Ambi lowers of KAC are not revolutionary nor do they improve performance or reliability of the rifle. I know a fair number of MIL and LE types and not one that I've talked to has ever said that an ambi bolt catch or mag release has or would likely ever make a difference in a gunfight. The natural lulls in the fight afford plenty of time to reload and use the standard controls.