I was surprised to experience that my rifle, which happens to be a 375H-ity-H, recoils less that the 300 magnums I've shot. I don't consider myself an Elmer Keith disciple, but I just like this particular rifle because it feels great and shoots great. I'd like it just as well if it were a 30-06, I suppose.
The thing about the magnums is that you still need to be able to shoot well to use them. Like trajectory and windage beyod 300 yards is still very significant to good shooting. I've talked to a few 300 mag owners and some are truly knowledgeable of the round and prefer it because they have learned to use it well and it is effective. Others just seem to take for granted that you can shoot out to 500 yards without knowing much about wind or trajectory.
Some magnums I like are:
1) 44 magnum in a revolver, and would probably like it in a carbine too.
2) 22 magnum. Nice round. Kind of expensive to shoot, but if you just hunt with it, it's not bad at all. It would be my choice if I did a lot of fur trapping or fur hunting.
3) 375H-ity-H. Very versatile in a rifle. Kind of heavy, but overall a very good combination when you consider the rifles and bullets that are available for it. That's the only thing I use for big game. I definitely would want something lighter if I hunted a lot in the mountains or did a great deal of walking while hunting.