This
"Superman has done just about everything, because he's had hundreds of writers.
Goku has had one canonical writer.
Honestly, I think that instead of being simple and just going with the original creators' Superman, which would of been mauled like a 10 year old facing a tiger, they decided to go with a jacked up, multiple retconned powers, as modern as it gets Superman. That way Superman could win, and then they'd get more publicity.
I mean, when there are multiple comics, most of them retconned, that feature Superman as a God, it's not going to be a fair comparison at all.
Plus there's the fact that GT was as recent as what, the late 90s? Superman, particularly his sun dipping power, is pretty damn recent. He's already got 40 some years of existence in writing against Goku, and then another 15 or so more."
Maybe now there is something more recent that we can compare it will make this more interesting.
http://www.saiyanisland.com/2013/02/super-saiyan-god-new-dragon-ball-z-battle-of-gods-scans/