I went down this path before in the AR-15 arena. Having spent more than a few times on active duty cleaning out nearly every square inch of the upper receiver on M16A1s and M16A2s, I wanted to lean in the direction of a piston operated AR. I heard many good things about them with just a few drawbacks (higher cost and heavier were the top two). I had the opportunity to fire an H&K 416 that an operator had available for me to shoot. It was a nice weapon, but I noticed something unusual about it. It wasn't just heavier, but front heavy. I suspected that was something one had to get used to. I ultimately broke down and bought two Stag Arms (piston model). They have shot very reliably and require very little to no maintenance or cleanup (normally just clean the bore). Stag also had a feature I liked, which was it wasn't front heavy like the H&K 416. I also bought a Patriot Ordnance Factory piston model for myself. It was heavier than the stags, but not front heavy like the H&K 416. Unfortunately, it does not look like Stag makes an AR chambered in 7.62/.308. POF on the other hand does make this:
https://pof-usa.com/firearm/revolution/
If the POF Revolution functions as good or better than my 5.56 AR POF, than it should be a pretty good weapon. It is relatively light for a .308 coming in at 7.3 pounds. Most decent pistons also have a gas regulator, so it makes it easier to work with a suppressor if you are going to use one.
One immediate difference you will always notice on a piston vs. DI weapon is the amount of cleaning time required post range. Pistons clean up really fast, unlike DI weapons.
My $.02 worth.
