They all work, I like the looks of the Featherweight so I'll go with that.
Oddly. I know several serious Stone Sheep hunters and not one carries a 'mountain rifle'. They all shoot full sized rifles, usually in a flat shooting cartridge. I know of two 7mm STW's, 1 264win, 300 H&H, 300Wby, 338win. There's lots of uneducated grizzlies in Stone country.
When your panting hard and the mountain wind is bucking you, or your just plain excited, the ultra lightweight is just a little harder to steady.