>>23Vis-a-vis fighting ability, I would counter that while Goku spends a lot of time training, it's actually pretty rare for him to fight opponents that test his limits. Years elapsed between his defeat of Piccolo and the arrival of Raditz; ditto between his fight with Frieza and with Cell, and between Cell and Buu.
Superman fights extraordinarily powerful beings like Darkseid, Doomsday, Lobo, Zod, etc on a much more frequent basis. In practical terms, he has to have more combat experience, and in my mind that trumps training.