I use .260 Rem for ranges out to 1100m for long-range field and military competitions, where I know I will be in the bipod-prone, fighting position standing, or other supported positions most of the time. It really starts to shine over other calibers at 500m, but it is not the rifle I want to lug around so much in the heavy barrel form that I have, even at 22". My Grendel is light as a feather compared to the AR10's with target barrels, and I can shoot the Grendel a lot with its lighter barrel without fatigue. The Grendel also doesn't suck a ton of powder when I load for it, so that means less trips to the store for powder.
When I have done 2-day long-range courses with a featherweight .308 dropped into a McMillan A4 stock, even suppressed, it beat the trash out of my face and head, and that was with 155gr Scenars. The gun still shot 1/3rd MOA all day long, since it is a Sako 75 .308 with an amazingly accurate barrel, but it was abusive over extended shooting sessions. Not so with the Grendel, especially when you go to a heavier barrel. It feels recoilless in heavy barrel format to me, without a brake. While it may be the slower cartridge for distance work, it is a great balance of weight, accuracy, and efficiency.