I think they are too dense, serious, melancholic and even bitter and hard to swallow. Mainly in Justice League.
I've been seeing classic Superman stuff and the thing about him in the bronze, silver and golden age (***Im not talking about the post-COIE Superman***) is that he's charming and likable. How is that entertaining? Because while we all knew he's perfectly assertive, he had to put an act as Clark Kent. At some points we think, "yeah, he could have Lois anytime, but he's sticking with his double identity thing"; but then again, at some other points, he makes us doubt, as if he was so invested in the Kent role that he doesn't know how to get out of it without taking of his glasses. I think that characters sells. It actually sold better than any of the new stuff. Watch a Christopher Reeve movie and tell me he's not likable. I dare you. I think it might be getting a even more serious and hard. In JL I felt he was way too serious.
Then there's Aquaman. Didn't read his classic stuff, but in JLA and the other media he seemed like a nice merry man. In the modern age, he was way too serious, which was a way to make seem togher and more relevenat, and it worked and it was even better in the DCAU. That being said, I liked the Brave and the Bold angle even more. He's relevant because he has the powers (he's a fast brick even outside the water) and because he has the attitude of a king with almost no insecurities. I normally hate character derrailments, but I'd prefer a version with *some* reasonable elements of that. An utterly "outrageous" Aquaman would be mistake for any serious DCnU. However, an Aqua-wait-for-it-man that might not be so cartoony, and can take matters seriously, but is still generous, adventurous, optimistic, loud and epic. Kinda like the Thor from the movies, any Brian Blessed character (the king in the first Black Adder), Beorn from LoTR.