A few things to consider, like barrel length and overall what platform you are shooting. I think with the NR variants there isn't a ton of extra gas to dissipate at the end of an 18.5" barrel. I think the best bet there is (if you really want something) is a diffuser of some sort. I have seen some advantages to using the Odin Works ATLAS 9, SJC Titan and the MBX block on some shorter completion builds, but all those builds are on Restricted platforms.
I would second the tuning, huge game changer for the PCC's, start with the right buffer and you have a very good chance of having a really nice shooting platform.