I can't answer if you are pushing for speed, but having done several centuries, or century+ rides which last an average of 6 hours each start to finish, I do know that if I try to subsist on nothing but short ride, gus, gels, protein bars and electrolyte drinks. I need some normal type food somewhere along the line. For me a peanut butter made with low fat peanut butter and whole grain bread, cut into bite sized chunks, along with a baggie of dried fruit chunks ( banana, apple, apricot and dates) which I can suck and mouth to keep myself busy and slivating.

Just a thought- when in doubt, the best food is the least processed,closest to real food you can find if you are accustomed to it throughout your diet.