How much experience do you have shooting the 338-300 RUM, 338 RUM and 338 Lapua that you mentioned? The capabilities of the lapua do not far exceed the capability of the RUM. What is the load and velocity you shoot that far exceeds a 338 RUM? You may have a particularly fast rifle but on average they are abut the same. Certainly not enough difference to make a difference in a hunting situation.
Listen, you want to lump the LM in with the RUM, then be my guest. I really don't care. I disagree, and you saying I am wrong, doesn't change my mind, as me saying you are wrong, won't change yours. So, I will make one final point and you can have the floor.
Out to 500 yards, you are right, in a hunting situation, there isn't a ton of difference between the two, but there is a difference. I know even at muzzle point, with a 300gr Berger and 92 gr of H1000, in a 26" barrel, I can get 2790 fps no problem. You will be lucky to 2600 with the same load in an 26" RUM. Furthermore, you can push the LM further in loading, where as 92 gr in the RUM is pushing the limits pretty quickly. That is significant in my mind when you take that downrange to long distances.
Is it a good round, absolutely. If you own and Edge or Lapua, is there any reason to replace it with a RUM, nope, not in my mind. Unless you love it. As evidenced by your voracious argumentative fury on the subject.
People think that just because a person shows that their rifle doesn't fit in their arsenal, that it is somehow a knock on that rifle. I am not knocking the 338 RUM. It is a fine round. It just doesn't fit in my arsenal. Neither does the Edge right now, but I would make room for it.