Follow up:
I don't believe "precision" and "AR" really belong together because they platform was never intended to be a precision tool. A precision upper would be made of steel, not aluminum. Too much flex in aluminum. ARs can achieve some really impressive results for what they are. But "horses for courses" applies here, too. Glocks run because they are sloppy as all get out. It's not a bug, it's a feature.
What makes an AR "quality"? Reliability? If so, then it's going to be overgassed and have more recoil than it should. (looking at you DD).
Or is it accuracy? If so, then it won't be as reliable when dirty.
Or is it durability? Then it won't be lightweight. Or cheap.
There are inherent limitations in the range of compromises you must make with a DI gun. You can optimize them for any particular direction, but it necessarily excludes some other desirable things.
And you most CERTAINLY will pass a point where more spending does NOT buy you more quality. I recently had the chance to check out an ultra-lightweight gun that will sell in the $3k plus range. For me, the value above any premium AR in the $2k range was basically none. A thousand bucks for a pound or two? not for me..
Sorry man, you can get 0.5 MOA in DI all day now. If your definition of useable precision is tighter than that, I want to see what guns you are looking at.
The largest group I have ever seen from a Larue, by the factory is right at 0.9 (3 shots). The owner regularly busts out groups in the 0.4 range (5-shots). My personal OBR is 0.45 all day, with a couple groups in the 0.36 range. That's with me shooting, and I'm not the best shooter.