I don't have the time or desire to research and purchase all of the components to build an AR. I would rather buy a good complete version that I can just go shoot.
I couldn't agree more that is why I go with a Mil-spec good to go rifle that I can add my own optic and sling to and run.
Several good/quality good to go rifles out there, the Colt 6920 meets the specs and a good price, I would at least use that rifle as a starting point when comparing rifles.