I have seen the death battle. while the numbers are slightly in super man's favor I still doubt he would win. while super man is used to fighting people weaker then him and sometimes just as strong as him he doesn't have the fighting experience goku has of fighting someone stronger then him or fighting as often against his equal. super man doesn't have martial arts. while super man does have the strength on his side he doesn't have anywhere near the firepower for distance attack and goku would read that early on in the fight. the fight would never be to the death. if it was then goku would lose just because he can't breath in space and the planet they are fighting on would surly be destroyed. it's been a while since I read this but I remember someone quoting Stan Lee that super man would lose to goku.