I haven't used both, just Kifaru, but I can see why some would say Exo wins in the day pack category. Seems like I could be carrying nothing to 20 pounds, and the Kifaru bag feels nearly the same (a bit heavy). However, as the weights get heavier into the bivy pack region, the pack doesn't feel nearly as heavy as it is. One of my hunting partners last year had an aluminum external frame pack that just looked bulky. He is a year-round runner and in pretty good shape, but I crushed him on the hikes (we are in similar shape). When we were stopped, he went down and picked up my pack, thinking it was going to be way lighter than his. In actuality, it was much heavier than his! I feel like the huge lumbar support makes me stand up straight, activating the biggest muscles in my legs, helping me last much longer under a heavy load.
