The commercial diameter receiver extension is a dead giveaway that Windham cuts many other corners. That means barrel steel, coating, testing and twist rate. And bolt and carrier steel, testing and staking. Often improper sight height as well.
That's why so many who care about quality pay more to go with Colt, BCM and Daniel Defense. Is it necessary, maybe not if you just plink at the range here and there. If you need a solid rifle then yes it is.
But there's more, why would anyone go with Windham which cuts the same corners that the old (and new) Bushmaster did (does) when you can get a milspec PSA for under $800? It just makes no sense to pay the same or more for a commercial grade AR!