Well, not yet, actually. I found a guy selling stripped lower NIB with all the goodies to put it together so I jumped.
I have a custom Mega Arms upper with a BCM 11.5" barrel and a LaRue rail I would like to throw on it in a pistol configuration until I can afford to Form 1 it.
Perhaps, a stripped M&P15 upper will come my way and I can snag that, as well. I'm not sure I would purchase a complete upper. I think those barrels have a 1:9 twist, and I would prefer a 1:7.