There is no question that high BC bullets drift less and drop less than those with a lower BC and, if you are shooting at long range, a big difference in BC can make a big difference in wind drift and drop. It can make a much greater difference than more velocity, for instance.
When I was shooting a lot of "F" class competition, I mostly shot a 6.5 with 142 Sierras or 139 Scenars and was satisfied with the performance of them. When I dropped a point, it was usually because I missed a change and it usually wasn't a case where a little better BC would have helped.
I shot a 6,5x55 because I felt that anything over 2700 fps to start was plenty. I also shoot 308's with 155 Scenars and, trust me, there is a noticeable difference between what a 155 30 cal at 2900 does compared to the 139 at 2750 and one is better off sticking with one or the other so as to not make too many mistakes in wind compensation.
When it comes to hunting, it's a little different deal. In the picture shown by Beretz, he hints that extra BC can help if there is a bull elk on the far hillside. In my mind, what can help even more is the ability to anticipate where that bull is going to be by the time you work your way over to intercept him. Different strokes. This difference in philosophy means I can feel just fine with 140 Noslers in the 6.5 because, chances are, I'll be taking the shot at less than 200 yards or, as usually happens, I won't be taking it at all;). A few inches of wind drift at long range is meaningless in this context.
All of this has little to do with the 280AI and more to do with what one is trying to accomplish. If the goal is to achieve the best long range performance you can, the 280AI will probably work fairly well to drive high BC bullets at decent velocities. I built a rifle like this in about 1980 and it worked quite well. It would drive 168 Sierras (which was the chosen bullet at the time) to about 2950fps. Other cartridges would accomplish much the same thing but the 280AI is popular today so it's not a bad choice.
If one just wants to build a great mountain rifle which will be good to carry and useful on big game, using bullets from 140 to 175 grains, the 280 AI (or the standard 280) is just fine. So is the 7mm Mag. GD