The biggest complaint I've ever heard....the *only* complaint, even....is the sights aren't quite solidly mounted. Here's a post of mine from another forum; "If you plan to use the ATI ghost ring shield, remove the sights and then mount the shield solid to your gun. Get it right. Next, lay a piece of emery paper, grit up, on the spot where the sights will be and carefully sand the sights down so they fit flush and solid. Take the shield back off and then remount the sights and then the shield. Get the sights sanded perfectly and the system is perfectly solid and works great."