The 280 shoots most bullets about 200 fps faster than the 7mm-08.
Both are hunting cartridges, although if my memory serves the 7mm-08 was adopted first by the silhouette metallica
crowd because it shot those lovely high BC bulllets through a short action with enough energy to topple the 500 meter rams. That game, as you know, is played with the shooter standing on his legs and shooting from the shoulder.
It was an easy jump from the metallic silhouette fields to the hunting camps. If a cartridge has enough energy to knock down a full-size ram target, it's got plenty of energy to knock down a full-size game animal. If you're reloading your ammo, it's easy to make the cartridge from .308 or .243 brass, it's an inherently accurate cartridge, and it fits well in light rifles that are carried lots and shot little.
I don't believe that many game animals can tell the difference between the .7mm-08 and the .280. Most deer aren't calibrated for a 200 fps difference.
The .280 is a great cartridge, but it suffered from Remington's idea on cartridge identification. At one time they called it the 7mm Express, trying to capitalize on the idea that it is a 7mm cartridge. If you're a 7mm fan, the 7mm Rem Magnum does the same job in the same action length. Then again, I don't know of any gun-writer that's championed the .280. I think we can say with authority that Jack O'Connor liked the .270, that Jeff Cooper liked the .30-06, and that Grits Gresham liked the 7mm Rem Mag. The .280 Remington, while always a fine cartridge in its own right, has suffered from a lack of identification, from Remington's own marketing ploys, and the fact that it is stuck between two iconic American cartridges.