I agree with Daryl that more than 4x is not needed for shooting at big-game. The advantage of a 1,5-6x42 compared to a 1-4x24 is the bigger objective lense and the resulting better light-gathering capability. At least here in Germany we most often hunt in rather bad light conditions, the animals start moving just before it is getting dark.
Usually I have my scope on 2,5x, sometimes more but almost never at 6x. If I cant`t see the animal with 4x, it`s just too far away for me to shoot at it.

Kalunga