I am going to buy a Kimber Montana as well, I will get the .300 as I backpack in Grizzly country and prefer the larger, heavier bullet. I have seen very large coastal and interior Grizzlies killed stone dead with a single Nosler PT. from .300 Win. Roy and RUM mags. I fully expect that the WSM will do exactly the same thing, I will try the 200 gr. NP as it used to shoot lifesaver holes in my old Mod. 70s in .300H&H, melud!
Right now, I doubt that there is a better option for the solo, backpacker-hunter who finds, shoots and guts, then packs out his own game. I do prefer even more gun for Grizzly country as do most of the really experienced bushwhackers I know in rural B.C., but, a .338 Win. in a rifle as light as the Kimber is just too much for me. I once considered one of those titanium Mausers that Ed Dillon made some years ago, but, the cost was too high for any real advantage one would get.
My thinking is that this Kimber in .300 WSM especially is going to sell in the 100,000s for years to come; it's hard to imagine a more practical rifle for most big game hunters in North America. Of course, I will keep my other rifles because I badly "need" them......................
