I like the old myth about Classic Stocks being better for recoil, as they deliver a rearwards push and do not raise up and belt you in the face.
After reading that a few hundred times, and shooting both classic and monte carlo stocks a few thousand times, the truth is pounded into you.
As for the 300 vs the 338, I think is it a matter of whether your interests lay in bullets or ballistics. Both are well suited to the majority of game either would be used, one shoots a tad flatter, both shoot well constructed light for caliber bullets well, and both have a top end bullet weigh that will suffice for all but the heaviest African game for which neither is legal anyway.
What do you like? Bullets or ballistics?
JW