Re: what's so special about SR-25's?
I have had two SR25s and a few other AR308s. I usually shoot factory 175SMKs:
LWRC REPR--would consistently get around .9MOA, but it could shoot heavier rounds better. If I handloaded, then I would have kept the REPR because it runs so clean and the side-charging handle makes it a breeze to dry fire.
GAP AR10 -- ~.85 MOA, but I didn't shoot it that much because I didn't like the balance
So, what's so special about the SR25s:
1) SR25s have been the most consistent shooters with a wide variety of factory ammo.
2) Something about the recoil on an SR25--comes back smoother than the other rifles I've shot--hard to explain otherwise. This was really what made me come back to the KAC. The way the rifle shoots gives me a better experience.
3) The guys at KAC have always been good to me when I asked for help.
Is it worth the cost premium? Only you can answer that. I sold my first SR25 to "upgrade." I regretted it almost immediately even though my later GAP AR10 and LWRC REPR were great rifles. Now, I'm back to a GAP-tuned SR25. My next 308 AR will be one of the 3rd generation KACs that just came out at SHOT.