The thing about the movie is that it assumes audiences are familiar with the characters so it doesn't bother giving you much in terms of their backstories. This would be a legitimate comparison to the MCU--Marvel built up their audience's connection with individual characters in solo movies. The DCEU skips that and though I think it's possible that you can start with a group movie then branch into backstories and still be able to make the audience connect with a character, BvS needed to work on that a bit more. The movie tries to intrigue you about the characters so that you'll want to watch the other DCEU movies to find out about them.
But that being said, BvS felt like a love letter from DC to their fans. It felt like DC was saying, "Here's what you've been waiting for, you deserve this! I'm giving you all the treats!" I'm not sure why people keep saying that the first part was difficult to follow (I had no problems keeping track of what was happening). The pacing IS fast but if you pay attention (which, why wouldn't you pay attention to a movie you paid for) then you should have no problems.
I had an easier time connecting emotionally to Superman here than I did in MoS. You could really feel how 20 years fighting crime in Gotham jaded Batman and chipped away what little optimism he had left for fighting crime. And the cameos of the rest of the Justice League! The cameos were everything!!
The movie's not perfect but it's definitely an improvement over MoS.
