They use good components, but they're just slapping them together, or so it seems, these days. OP, if you're prepared to go into the upper, tighten gas block, tighten barrel nut, etc, then you should be okay. If you're expecting to shoot it out of the box, it might work, might not. If you're building your own upper from CMMG parts, then you're good to go - the parts are good.