I saw JL with the kids last weekend and I really enjoyed it. It's a popcorn movie and I know it going in so I try to enjoy it in that manner and not pick it apart.
I do feel like DC movies are a little behind the eight ball with fans for a couple reasons. First, the combined cinematic DC universe getting started in earnest as late as it does, sort of feels like a copycat to the successful work done by Marvel with their Avengers series, fair or not. Second, previous stand alone DC movies, like the Superman films from the 70's and the Nolan Batman films, are so deeply embedded into the consciousness of movie lovers that it is inevitable that comparisons and departures from those iconic films make for a tricky minefield for screenwriters and actors.
But I think that done correctly, people can get beyond that stuff. The Tim Burton Batman movies played up the comic book aspect of the characters and people had mixed opinions on it. When the Dark Knight movies premiered, everyone forgot about them forever. A new standard was set. Where Brandon Routh flopped as Superman for trying to mimic Christopher Reeve, Man of Steel delivers something much more original and appealing. I think this can be achieved for the Justice League as well.