There's one difference here. A "Portion" of the Fed proceeds goes to either cancer research or The Wounded Warrior Project. Both are worthy causes.
I've used both kinds of Fed stuff and the GCs. Both give decent performance and both hulls can be reloaded. I load them once for the pumps and pitch them after.
In Gun Clubs I go for 8 shot, 1 oz.
The Feds are 1 1/8 oz, but the speed's rolled back to 1145 FPS. I still notice the kick more than the 1 oz GCs, but it's not that bad to me.
One 870 here does not "like" GCs, and balks on them a bit. All other shotguns here have zero probs with either...
Get what you want...