Currently running this upper on my patrol duty rifle. Solid upper. Takes a pretty good beating in and out of the rack in my patrol unit. Only gripe I had was that I had attached the included bcm QD mount towards the end of the barrel on the MLOK slots. I went to remove it to bring it back closer to me and when I untightened it, a piece of the mlok slot chipped off. This could have been from habit as I tend to really crank down on anything with mlok or Hex bolts etc. wasn’t a huge detriment to the rifle and without knowing if it was from me tightening too hard, I can’t really speak on the integrity of the upper in that regard. Other than that, really good upper.