...Or Beretta’s polymer carbine CX4 mated to the PX4s or 92/96.
In 5.56 pistols, there seem to be more choices every day. I own the KelTec PLR16. Haven’t fired it at a distance to truly check for accuracy but I do like it.
Were I in the market today (& assuming the money to play with) I might instead choose one of the buffer spring pistols for the Sig arm brace. Then again, I like the trim profile of a rifle round pistol shaped like a pistol-gripped shotgun, instead of the buffer tube sticking out there looking all ugly.
YMMV
My interest besides compatible ammo & mags is there seem to be certain advantages in home defense use with 5.56 as opposed to 9mm or such. (Of course something shorter like a pistol being easier to navigate inside a house)
(obviously best of all worlds would probably be a tax-stamped SBR in 5.56)