I had one on backorder for 8 months or so (ordered just before the Nov. election) and gave up. I bought a Spike's 9mm M4 barrel and built my own. I decided to build another one, so I placed another order two months or so ago - waiting again.
I hope they make TONS of them to fill the orders and get to mine too. I hate waiting.
ETA: Ah, holy crap. PK Firearms has them in stock. I ordered and was charged up front. He charges a cancellation/restocking fee, so I'm locked in to that one.
You guys looking for one, feel free to dogpile over on PK Firearms.