I would have thought the extra 10 grains becomes relevant when you are operating at the margins. Under ideal circumstances, a broadside shot under 200y with a clear aim, I am sure the extra 10 makes no diff.
But under less than ideal circumstances, maybe it might make some difference. I don't doubt it certainly can.
The extra momentum might only be relevant a small percentage of the time. But the same could easily be said of the slightly faster MV and better BC of the 150g bullet. How often does that make a difference? About the same percentage of occasions, I'll wager.
