Innova was the first by at least a couple of years to produce this paper. After Crane produced the Silver Rag, Innova was the first to make a brighter white fiber gloss media, then followed by Ilford, then everyone else. We were using the Innova US Gloss and the Semi-Gloss, that I like better, a long time before Epson got into those products.
The differences between the Innova and EEF are the weight. The EEF wasn't available in rolls for a long time because of its thickness, which as many have pointed out isn't always a good thing, depending on your printer. If they offer it in rolls now I assume it isn't as thick and difficult to flatten.
I recently bought a roll of the Moab Colorado and it looks and profiles the same as the Innova. I assume Innova makes this for a number of companies now, maybe with very subtle differences so they can claim they aren't the same. Epson used to say the same thing about the papers that Premier Art made for them, and continue to make for them too, with very subtle differences if any. Epson has always contracted out their paper production of course. Since they are such a big customer I'm sure their suppliers are sworn to keep their mouths shut about it.