I have used 150, 165, 180 , '06 bullets, vanilla and premium, on about half or the 21 or 22 moose I've killed. Not counting several road-hits I've finished with a .22Mag. (not mine - trooper finished that one with 12 ga)
It doesn't matter, used and placed appropriately. Personally, I prefer the 180, just cuz.
Calibers I've used, are .243, 30-30, 308 Norma mag, .338WM, 270, 30-06, and 12 ga with slugs. Used and placed appropriately, that too just doesn't matter all that much. Dead is dead.
I'll second pricedo above.
JJHack, who used to post here, and has far more experience with deading animals than I, stated that he thought the 165 is just about ideal in the 06, Won't/Can't argue with that - but I still like the 180.
Aaguard, shooting into wet newspapers I think, concluded the 180 had better penetration than the heavier bullets. Not sure how important that is (personally, I like blowing holes to daylight), and I also think that he did not test premiums at the time, only vanilla.
Don't overthink it - accuracy/placement with your rifle is more important than flavors or serving amounts, within reason.
