Past 700 yards is where the 300 RUM shines. I've hunted with a 300 Win Mag for the last 16 years. Just got a 300 RUM and can't wait until next season. I lucked into a bunch of brass though.
I have had a lot of different chambering's and the 300 win mag is at the top of the list. It's easy to load for and is an absolute hammer. The recoil is managed easy with a brake and components are easier to find. I shoot 230 grain berger OTM's at 2710 fps and it shoots awesome out to 1500 yards