First off, all I have to say is WOW! I have been bouncing back and forth between ADM and another upper and lower for a few years now and I cannot explain how thankful I am I chose ADM. The all around care of packaging to the detailed instructions you receive with the product is above and beyond. The ambidextrous controls are smooth and operate flawlessly. It is so easy to charge and lock the bolt to the rear without removing your hand off the pistol grip. And the bolt release being on both sides has helped drop my reload times down significantly! I will admit it took a little getting used to, but once you do you will be very thankful. The customer service has been a real pleasure to work with too. They are very busy but I sent an email like the website said and they did get back to me in a reasonable amount of time. I have 100% confidence in saying that ADM products are built at such a high quality that I will always go with them for future AR builds. Anyone I know who wants to build an AR will need ADM parts and products.