There are people out there obsessed with this kind of stuff and extremely knowledgeable about it. My observations, though, are casual. As a kid I found the DC comics to be more polished than the Marvel ones. But Marvel was very flashy and colorful and got a lot of attention. In time, even though it may have started like Avis to Hertz, it became a very popular and successful brand. Also, in general, the Marvel movies have seemed to get more widespread public appeal. Personally, I find DC to have a little more depth. But there are many exceptions. I like the Ant Man/Wasp movies a lot, for instance, and they're Marvel. Those movies are the most notable exception for me. Ant-Man seems as much like a DC character as a Marvel one. Although I don't know the details, supposedly he is based on an obscure DC character called the Atom which I know very little about. As of yet, I haven't found anything more interesting than Evangeline Lilly's role as The Wasp in the Ant-Man movies.