I'm going to stick to what I know and I've not shot an elk. I would speculate that the heavier bullets would be better. But I would probably pick a 165 gr Barnes for an elk if I was using a .308 or 30-06.

Now I want to be clear if you hunt and shoot game at ranges past 600 yards then the Bergers may be a better choice. You are dealing with slower velocities out there and lower energy levels.
Time of flight keeps me from shooting at game that far.