The old light magnum rounds would not cycle in semi-autos and pushed pressure right to the limits. Supposedly the Superformance ammo gives comparable velocity, without excess pressure and is safe to use in semi-autos.
I've tried it in my 30-06 and 308. It did not impress me in the 30-06. Accuracy was borderline and speeds were not impresive. My handloads with a max charge of H-4350 were within 50 fps of the Superformance loads and much more accurate.
My 308 liked them much better. Accuracy was not quite as good as my handloads, but perfectly acceptable, at least as good as any other factory load I've tried. Velocity was not as much as advertised, but much better than I can get with my handloads.
They are not overly expensive and worth a look. If they shoot well in your guns they would be a viable option.