The Marvel Cinematic Universe appears to be carrying on with little to no problems at this point. While DC's Extended Universe is still fairly new, Joss Whedon thinks he's seen enough of it to really understand the different ways the two companies go to market. From his perspective, neither company is necessarily better than the other, but rather, they have different goals with their movies.
This may be the most simple, and the best, description of the difference between the two companies that we could conceive of. Joss Whedon's comments to Complex feel right on the mark. While Marvel movies aren't without style, the story is clearly the thing the company is focusing on. They're trying to build a coherent universe for all of their characters in the movies in the same way that they did in the comic books.
On the other hand, DC, or at the very least Zack Snyder, wants to recreate the comic book experience in the movies. This means that many of his shots either come directly from comic book panels, are meant to evoke the feeling of a great still image from your favorite comic.
Of course just because the two companies go in different directions doesn't mean that that either one of them is right. Joss Whedon has worked with Marvel and even he has admitted that doing so is tough. Marvel has a reputation, justified or not, that the story is so important that it overrides whatever an individual filmmaker is trying to do. Edgar Wright ended up leaving the director's chair of Ant-Man over creative differences with the studio. From all accounts, it sounds like his idea for the film was a bit "out there" for what Marvel wanted. Story is great, but it has a cost.
DC, on the other hand, has tried to champion the idea that they let the filmmakers do what they want to make great films. This results in the style of each director coming through, to be sure. However, many would argue that DC thus far lacks the cohesion that has made the Marvel movies successful.
Do you agree with Joss Whedon's assessment? Let us know what you think in the comments.