I bought a PWS MK216 about 2 years ago. I shoot suppressed and am a lefty so I thought I would go piston. It's cool and seems to shoot nice. My only gripe is the weight. I know AR10's generally are heavy. I don't honestly have plans to hump it around.
I am not a long range shooter, but want to keep a semi auto 308 with great ergos in my safe. Realistically is there any advantage to selling and getting something like the SCAR? It seems they are pretty light for what they are. Also need to change lowers to go with my large collection of SR25 mags.
My other thought was to build off of a Stag lefty upper. I'm not too worried about parts compatibility since the AR 308 world is a bit of a jumble anyway.
Another thought is the short frame AR 308. Just not sure if they are sorted out yet.