My dad uses a 300 win mag with a brake. I don't think it kicks any harder than my 30/06. Recoil is an important thing to consider. A softer recoiling rifle is easier to shoot accurately. Plus with the .300 or a .338 you can buy ammo almost anywhere people hunt elk. Neither of them are barrel burners either, at least as far as magnums go. Whatever you happen to choose practice, practice, practice from field positions.
What is all the hoopla over brakes? I've got a .300 WBY with a factory brake and it works. I've heard people badmouthing brakes so much and when I shoot my .300 I'm thanking God I have one on this rifle. Mainly I hear people bitch about them because they make people at the range mad because of the side blast and noise. I say you should be wearing hearing protection at the range and it wouldn't bother you. You're one of the few here that has something good to say about them. I'll putg it this way, If my 300 wasn't braked I wouldn't shoot it. I wear hearing protection and my brake is wonderful.
