Fast, responsive, and easy. They even email your FFL dealer for you. They are very accommodating (unlike some other gun parts dealers and manufacturers), so much so I would rather buy my lowers from Classic Firearms than buy from any other popular manufacturers/retailers directly. (Looking at you PSA, Aero Precision, AT3 Tactical, Spikes Tactical, Anderson Manufacturing, Battlehawk Armory, Primary Arms, Brownells). Great experience, great people (except Jason, he is a gun snob. Jason and James Reeves should do an Mk18 video talking about how Gucci their guns are. Kaya is the best and most down to earth presenter.