It would surely depend on what you're shooting with it, but for 150# whitetail deer, probably no appreciable difference. I have both calibers but have only shot 1 deer with the Whelen and none at all with either 8x57. But I was impressed with a medium sized northern PA buck's reaction to the Whelen. Quartering shot at 55 yards with 225 Nosler BT knocked him back on his haunches, literally.
For other, bigger animals, maybe, but I've not the experience with them to do anything except quote ballistics from manuals and magazines, which you can read for yourself. For deer at reasonable ranges you're into 'how dead is dead' territory - just pick the rifle/cartridge combo that appeals most to you. -WSJ