I can't bring myself to an AR spot. I respect their symbolism, and for someone who LOVES "light, fast, useful" (scout-style), I should adore them, as they really make the PERFECT scout-rifle.
When holding them in the store, I love the ergos - the mag release and safety are in the perfect spot for me. Their balance isn't bad, and their weight is nice and light.
However, once I pull that "tik-tok" trigger, and feel the "sha-shooonk" of the recoil spring, and I'm still feeling movement in it WELL after the bullet has left, I lose interest. I'm sure if I spent a whole boatload of money on an upper of a different cal, and tuned the recoil spring, and altered the gas-block to optimize the action, then reinforced the bolt and added a different buffer and...yeah, you get the idea.
On AR-10's, if I want a .308 SA, I'll take a FAL or a BAR for the same $$ as a GOOD AR-10.