There has been less and less difference since DC Marvelized itself back in the early 70s. That kicked into high gear in the late 70s and early 80s when guys like Englehart and Wolfman switched over. I'm surprised younger readers would think there's any more difference between Marvel and DC than there is between Coke and Pepsi.
Back in the 60s, there was a huge difference. That's when Marvel's small-universe and feet-of-clay approach was still fresh and DC was still doing it's off-the-wall psychedelic thing. There was much more variety in comics in those days.