A lot of good input here. I would agree that if you already have a 7mm rem mag, only reason to switch to 7PRC would be if you wanted a new rifle. Same thing with 300 win mag vs 300PRC. The PRC rounds are updated versions.
All that said, if looking for a general do it all North America rifle, I am personally leaning toward that 7mm bullets in a 1:8 twist barrel. I do not think the 7 PRC is going away, and it will remain popular for a long time. That said, the 280ai would be the second cartridge I would consider and I feel the 7PRC popularity will also drive the 280ai to be even more popular.
It will handle up to 168s just as well as the 7PRC (with a 1:8 twist), and will handle lighter bullets for pronghorn, deer, etc. a little better. With a 160 CX, the 280ai is within 30fps of the 7PRC, with a 162 ELD-X it is 50, and a 168 VLD it is within 70. The issue becomes seating depths when you get to the 175 ELD-X where the the 280ai is 130 fps lower.
If you handload and are building a custom rifle, these change a bit with the 280ai being even more versatile and easier to handload. Longer barrel life, less kick, long brass life, etc.