"Batman v. Superman: Dawn of Justice" is... Not awful. Not really GOOD, but almost, maybe. Both the title and the running time imply that it is going to be pompous and bloated, and it IS, but it has its moments...
Tolkien tells us that the first goal of any piece of fiction should be "a good story, well told." What we have here is a mediocre story indifferently told. The plot is well enough presented that my brain cells were NOT committing suicide in protest during the movie (as is usually the case during YA-based blockbusters), but ever since the movie ended, every time I think I about it I find yet ANOTHER plot hole. The thing was about as watertight as a burlap sack.
The characters were problematic. Superman needs to be fundamentally optimistic and in love with a human race that he truly believes to be good, or he becomes a monster; this rendition has him about three-quarters of the way down that path. And the Bat is insane relative to the historical portrayals of the Bat, which is saying something. The script never decided whether Luthor was phenomenally lucky, or really the smartest guy in the room, and this added to the confusion. Lois comes across as intelligent, but vulnerable rather than thick skinned and relentless. (Lois Lane in heels? ALL THE TIME? Really?) Diana... OK, Diana was amazing. Cold and aristocratic and impossibly poised, and yet also REALLY fond of having blood on her knuckles. (And remember, I am NOT a Wonder Woman fan; I think she is a stupid character. But I am, to my surprise, willing to be converted.)
The casting, on the other hand, was amazing, and the actors did wonderful things with what they were given. Amy Adams was perfect for the part as written, but as stated, the character as written completely failed to fill Lois Lane's ecological niche. Jesse Eisenberg never really found Luthor, but that would seem to be because he wasn't there to be found.
Finally... The last special effect of the movie is REALLY dumb. It says something that needs to be said, and I have not yet come up with a better way to say it, but... Dumb.
So... Better than "Man of Steel", certainly. Still not really good.