Great all around upper for your ar-15 needs. - Aero Precision M4E1 Threaded Assembled Upper Receiver

Great upper with good machining, finishing, style, and fitment. There's not much to complain about here, only thing I can think of is their picatinny rails are "enhanced" with the middle part having been machined down maybe to minimize weight? It will still function and work as a standard 1913, but if you're obsessive about uniformity than it might bother some aesthetically. Fitment between my lower left-to-right was typical, a little slop but nothing terrible or distracting. Front to back was solid with no movement which was one of my concerns since the previous upper I replaced would actually slide forward and rearward. These are great uppers in-stock for the price (post-CVD), but the only thing I wish they changed is how they cut out its piccatiny rails. Just make them normal so they match up with most aftermarket FF hand guards.

OP had lightening fast shipping, receiver was delivered in 3-4 days.