M-4s, properly lubed, should get us through near-term CQB situations. As far as a "next generation" replacement, the OICW seems to be far from perfect. It is heavy, bulky, and armed with a 10" barrel firing 5.56mm that will greatly reduce range, accuracy and terminal ballistic performance. The OICW's 20mm top-exploding projectile has yet to prove its utility, particularly in urban CQB.
Why is it that we don't add / mix in a few dedicated M14 (or equal)and 12 ga. shotgun carriers amongst the M4's and SAW's within a platoon?
Seems to me that it would help expand long range and close-in capabilities.