Have you run both tires in question personally? Hard to have a valid comparison by reading specs alone.
Anyone that I have met who switched to Exo Grapplers from any other tire seems to love them for being stiffer and better traction. They are showing up on more and more stock-trailer-hauling pickups around here.
They're tough/stiff like an M-55 but actually have good traction on packed snow-ice without having to have studs.
