As you mentioned about the change to the BCG, it's supposed to be "safer". If your old setup worked for you, I wouldn't make the change. RA will mill your old lower to make it compatible with the new system if you want to. Not sure what they're charging for the service and/or if they're offering a reduced rate for the new parts.
"Necessity is the plea for every infringement of human liberty. It is the argument of tyrants; the creed of slaves."-William Pitt the Younger
Figured I'd post a picture of the pistol I got from Kermit. 10" barrel, mini length. Love the tailhook brace. The sight is the Meprolight M21 reflex, with the triangular reticle - it's the only reflex sight I've been able to find that that doesn't seem to be affected by astigmatism. Muzzle device is the BRT "Covert Comp" linear compensator.
Very nice pistol, looks sharp!
"Spes Mea in Deo Est"--My hope is in GOD
The antidote for fifty enemies is one friend.--Aristotle