I can't find a KAC anywhere within a 1 hour radius of me. Had one place say they should have a couple in 3-4 weeks. I'm going to hold off so I check it out. I'm not in any rush.
I may be telling you something you already know, but the big difference b/t the KAC and other AR’s is the E3 bolt. The design makes for a much stronger bolt and finding someone who has had one break is like finding a unicorn. The bolt is expensive but you probably won’t have to replace one. Another difference is the gas system length. It is b/t a mid length and rifle length gas system that makes for a really soft shooter. Pleasurable to shoot. I have an older mod1 that will not shoot underpowered steel cased ammo but I wouldn’t shoot that stuff in it anyway. The mod 2’s have further improved the gas system, so I’m sure they are top notch on that front. Another big thing with the KAC in my opinion is the weight. The lighter the better as long as it is still durable. KAC’s are ambidextrous, which is a big deal to me b/c i shoot lefty but I think it is important to be able to run the gun from both sides. There are other makers doing ambidextrous these days though.
I have Geiselle triggers in other ar’s and they are nice. The SR15 has the Knights 2 stage trigger which is nice, just not quite as nice as the Geissele. That said, I wouldn’t buy a rifle to get the trigger.
Go to ar15.com and read personal accounts on different brands. That is the best way to make a somewhat educated guess without actually spending time with each rifle, which is close to impossible for most.