It's not good, it's not bad, it's just meh.
There are some individually good bits, there are some individually bad bits, but my overall impression was just that it was kind of dull. Also dark. Dark and dull.
If you want to see spoilery and very snarky text review, Rob Bricken has come to the rescue as usual with a Spoiler FAQ:
If you want to see a spoilery but less snarky video review, there's this:
If you want to see a much longer spoilery review (an hour long, and i haven't actually finished it yet myself) you could check this out:
Here are my non-spoilery thoughts:
Good bit: The movie practically opens with Superman getting some comeuppance for inadvertently murdering thousands of people in Man of Steel.
Bad bit: It doesn't do a great job of making that comeuppance feel meaningful. After processing Rob's Spoiler FAQ, i suspect that Snyder still doesn't understand that Superman killing lots of people is bad, and therefore was unable (or possibly just unwilling) to invest it with as much emotional weight as it deserved.
Good bit: Batman was a kinda okay character.
Bad bit: But the movie _actually_ opens with yet another goddamn retelling of Batman's origin story.
Bad bit: And Batman also murders a lot of people.
Bad bit: Also, Batman either doesn't seem insane enough or seems too sane, depending on which way you want to approach things.
Good bit: Wonder Woman was awesome.
Bad bit: Except for the part where she sits down to watch a trailer for the next movie in the series.
Bad bit: Also, there are way too many dream/vision sequences in this movie.
Bad bit: There are more jump scares than i want in a movie. (Correct number for me: 0)
Bad bit: The trailers are very intentionally misleading about the nature of the movie. (Big surprise, i know.)
TL;DR: Too many plot threads that weren't explained well enough and weren't integrated well enough, too many people doing weird things for insufficiently explained reasons, and too many weird things happening with no good explanation whatsoever. And some good action bits mixed in with all the other strange, dull, confusing stuff.
I think that's about as much as i can get into without spoilers, which i will save for the next (or technically, previous) post.
Edit: Oh yes, i also think it made a bit too much use of quick cuts during action scenes and a bit too much shakey cam during non-action scenes. My tolerance for that kind of thing is pretty low though, so it may not bother most people. (Such things don't make me feel sick like some people, they just annoy me.)