When it is all said and done, " pay your money and pick your poison"
That' s about the best answer to tis question. Everyone has their preference on which diameter of bullet to use but the simple fact is that all three of the WSM' s are more than enough gun to hunt any of the hooved animals on this continent very effectively. Each one has something going for it over the other two like the .270 having the flatter trajectory, the .300 having heavier bullets and the 7mm being a good compromise between the other two. No matter which one you pick you will not be under gunned.