I bought a used DD Omega 9 off of a friend and put it on a BCM Middy 16. Right before the panic and immediately after Nov 6, 2013 I decided to buy another middy upper. This AR I wanted a 9" rail, but I didn't want to spend the money for a new DD. I had an old MI GEN 1 carbine length rail on my very first upper and decided to try the MI again, the price helped make that decision for me even faster lol.

I love the GEN2 Drop-In. It has more of a round profile than the Omega 9 and it may not lock to the barrel nut, but its damn sturdy.