There is a reason why Batman and Spider-Man have eclipsed characters like Superman and Shazam. It takes a very skilled writer to get the best out of characters like Superman, but even a mediocre writer can get a passable Batman story onto the page. To me there is this weird phenomenon in comics where the more powerful a hero is the more infrequent the great runs on them are. I think it has to do with the fact that there are just more things out there that can believably challenge a street level hero (or even a mid tier hero) then a heavy hitter.
Does anyone else notice this or is it just me?