Last year I had to make a similar decision as I bought a new rifle for my first trip out West (Colorado). I had a .30-06 but wanted something that could really reach out if necessary. After listening to many on this site, reading articles, talking with gunsmiths, and so on, I realized there was no right answer, just a bunch of opinions.

I decided on the .300WSM and I'm very pleased with its performance. I still enjoy the .30.06, but I seldom use it anymore. The .300 WSM recoil is very tolerable and the caliber far out performs the 06. I use Federal Premium Ammunition - they load their .300 WSM ammo to achieve slightly better ballistics than the .300 Win Mag.