All currently available Ar-15s are good. Some are better than others.
I have a Bushmaster "Dissapator" 16 inch barrel AR and I dearly love it. it's a great gun.
But it isn't even in the same league with my Colt 6940.
Like comparing a Chevy to a Mercedes. OTOH, if you can't afford a Mercedes, the Chevy will get you around town just fine.
So, as the saying goes, "you pays yer money and takes yer pick."