Off the bat (pun intended) I'm going to say this is not a great film. While it has it's moments (I've got some mileage out of Amy Adams in the bath already) it has a raft of problems.
The internet's freak out over Ben Affleck being cast as Batman/Wayne is, as you would expect, largely unfounded. He does a pretty good job as both Batman and Bruce Wayne. Henry Cavill's Superman has grown somewhat since Man of Steel and is a far more confident character. Gal Gadot is only in the film for 10 minutes but she does a good job with Wonder Woman. She's actually the most interesting character in the film, probably because both Batman and Superman have been done to death.
The Doomsday battle is good and Doomsday is actually far better realised than you would expect from the trailer. The conflict between Batman and Superman is good too. There are some also some nice nods to the comics and other media. Somebody is clearly a fan of Excalibur but I have to wonder how many people under 30 got the end battle parallel. It's even more obscure than the post credits sequence in Deadpool.
The choice of comic stories to use as inspiration is weird. Not sure mixing the Dark Knight Returns and The Death of Superman was ever going to really work. If I may become arty for just a moment, they have very different palettes. Blending them is going to leave you with a mucky brown. There are times Batman v Superman felt like two different movies cut and pasted together. Perhaps because I am familiar with the source material.
The movies biggest problem is that the middle section of the film is hopelessly tedious and creates a movie that feels overly long. It really flags I'm not sure the planned 3 hour director's cut (R-rated or no) is really going to help the film in that respect. The films labours under a director who clearly thinks he is doing Art (with a capital A). It's awash with dream/vision sequences and failed attempts at depth. I feel like I am describing all Snyder's movies here so we really shouldn't be surprised. The shoe-horned attempts to set-up the Justice League movie don't help either.
If you've watched The Watchmen (or almost any Snyder movie) you will appreciate the problems Batman v Superman has. Watchman manages to carry them and survive (mostly) in a way Batman v Superman does not. Hmm. Maybe an R-rated, 3 hour cut will help after all.
Jesse Eisenberg, *sigh*. He is awful in this film. To be fair I've never really rated him in anything. He clearly thought he had been cast as the Joker in a Batman movie. Maybe it wasn't his fault. Maybe he was doing as directed but then again maybe the film had to but cut around his horrible performance. Marvel have managed to skate by with less than impressive villains but they've never had one that was just shit. It is a depressing state of affairs when the best live-action Lex Luthor we have is still Michael Rosenbaum's in Smallville. Sorry Gene Hackman, your Luthor sucked too.
Now all that being said, I think the media/critics are shitting on this film from a great height. They have clearly singled it for some "special treatment". I suspect they really don't like Zack Snyder. The Hunger Games: The Mockingjay Part 2 is 50% more tedious than Batman v Superman and that film is well thought of.
Does it pass the Blu-ray rewatch test? By that I mean will I watch it again when it is released on Blu-ray. It does, but only just. I may wait for the Director's cut to do so.
How I picture Marvel Entertainment right now.
Batman v Superman: Dawn of Justice - 5/10 (Must try harder)