I've owned two, a nitride 5.56 and a stainless 300BLK, both 16" carbine setups. I've been very happy with the quality of the bare uppers - good barrels, good assembly, the receiver seems well machined, etc. All the other components I'm using with them come from other companies (BCM or LMT bolt carrier group, charging handle, etc.). I'll note that they use straight pins instead of taper pins on the FSB (adequate but not milspec) and the gas port seems large on the 5.56, but I'm quite happy with them for what I paid.