I am begrudgingly a big fan of the 11.5" SR-15 MOD 2 CQB.
I do not like the aesthetic of keymod, but the weight loss and utility is hard to argue.
Not getting into the Keymod vs M-Lok thing, I don't have sufficient data to disparage either.
The Mod 2 gas system is neat, and the guns are ported to run well both dirty and suppressed.