What I liked best about the old DC was the superhero community, and how everyone knew each other. And the legacy heroes. And then they got rid of that.
Marvel had some connections but for the most part it was more separated. And I liked that, especially since the world was more sinister, mutant persecution being an example of that. But with a larger focus on shield, that's sort of gone away. And now Marvel is the one with all the legacy heroes.
I preferred how DC did it, where the original hero(usually) took them on as a mentor.