This isn’t too spoilery, but mileage may vary.
It moves along and packs in a frightening amount of story. (Stories, really. Dark Knight Returns and Doomsday. Plus more.)
Sets up a few other things that look interesting. (Justice League, anyone? Hopefully they won’t all fight each other the first time they meet. That would take a long time.)
A fight occurs because one character is deemed to be an unaccountable loose cannon and the other is committed to curtailing him. (In a reversal to how you might expect that to work.)
Batman ends up being a friend to Superman, but don’t think too closely about how they get to that point. (Fight to the death starts, fight to the death ends, because… reasons. Well, names, anyway.)
Lots of questions about all sorts of philosophical issues get raised, and not really dealt with. (Notwithstanding the person who asks most of the big questions seems to be crazy as a Junebug with daddy issues.)
Wonder Woman shines brightly.
Waiting for more.