I'm not a fan of Affleck's Batman. He's not what I would want from a Batman movie, but just in terms of this film, I don't like the suit, Affleck doesn't look good in the cowl, and...well, he's basically a second villain for most of the movie. His goal in the movie is to commit murder, and he has an unpleasant personality, and him turning around at the end isn't enough for me to want to cheer for him. Which wouldn't matter so much if BvS was focused more on Superman as a protagonist/hero, but while the movie revolves around people's feelings about Superman, Clark himself isn't developed as much as he really could be.
Which leads me to something I've been thinking about. Clark/Superman caring about the people close to him was never in dispute. Bruce had a nightmare about Superman becoming evil because Lois died, Lex wanted to prove that he wasn't a savior because he would put his loved ones first, and the public didn't know or concern themselves with his friends and family. I don't remember a newspaper tagline like "What if Superman doesn't love his mom?"
Putting aside expectations someone might have about what a Superman movie should be...given that the conflict revolves around his devotion to the well being of people outside of Lois and Martha, it's counterproductive that his major emotional beats near or at the end were focused on how much he cared about Lois and Martha. His daydream of his father was about depending on Lois, Bruce decided not to kill him because his love for his mother called to mind Bruce's father's love for Bruce's mother, and before he died killing Doomsday he told Lois that she was his world. What the ending needed was a big moment where he sacrificed himself without it having anything to do with Lois or Martha, to emphasize that he cared about people in general.
I didn't really mind that Lex was an erratic dou****ag, but he just laid it on too thick as often as not. The "ding ding ding" thing was like a Saturday Night Live skit. Wonder Woman was cool, as was her theme song. More than anything, BvS made me want to see Wonder Woman. I'm cool with Lois and Alfred, too, and Fishburne continues to play a good Perry White, and I liked Senator Finch and Mercy Graves while they lasted, for that matter.
Most of my character complaints would be directed at Bruce and Lex and to a lesser extent Clark. I didn't have a problem with him in Man of Steel, but Cavill was sometimes wooden in this. It's not really the best sign when I'm watching a movie about Batman and Superman and Lex Luthor and I find myself more interested in this senator or that henchman, and hey, what was the deal with the horse? There was a random horse during the Kryptonian attack, and then there was a cop on a horse during the hearing explosion. Is Bad Horse the secret mastermind of the last two films? Because that would actually be pretty cool.
The movie had good action in it and special effects and a Batwing and Batmobile and all that, so yeah, that's all well and good. On the other hand, it was heavyhanded at times. It's a hard movie to give an overall assessment of because it's long and there's a lot of different stuff going on, and some works and some doesn't. Perry and Clark arguing over journalistic integrity, good. Bruce's Manbat nightmare, not so much. Overall...eh.