Good bang for your buck - Aero Precision M4E1 AR-15 16in 5.56 Mid Barrel Complete Upper Receiver with Flash Hider

If you are looking for an Upper Reciever that is a good bang for your buck, this is definitely one you should consider. It looks great, feels great and is lighter than I expected. The only down side is the rails on it aren't as long as I would like, if you like to run a fore grip a little closer to the mag well or a bipod with a foregrip then you wouldn't be able to or it would be a little too crowded.