Well, I got to catch this tonight.
The good:
The interactions between the League. I thought this aspect was handled well, overall. I enjoyed seeing Affleck and Gadot on screen together. Their chemistry was palpable. It worked. I thought Cyborg was done well. Now, as for the character, I am certainly no fan. That being said, Ray Fisher was a welcome surprise in the role. I thought he got the character right for the most part. He had a nice little arc, as he comes to terms with his identity. Cyborg came heavily from Justice League Origins (new 52) by Geoff Johns.
Superman! I was happy to see him be happy, cheerful, and resembling the character that we read about in the comics. That being said, I think Cavill was best overall in MoS, as Clown stated. But he was pretty on point here I thought. Now, as for how Supes got to where he is, that will be further below.
I liked the first scene with WW in it. I think Gadot is just fine in the role, her lack of great acting aside. I think she cares about the role, and that she enjoys it. And I think that comes through in her performance. She kicks ass, which is awesome.
The bad:
Steppenwolf. Among the worst villians in a CBM. Although I would say he was better then Enchantress in SS, but that isn't really a complement lol. He was one dimensional, and he was just very flat and boring. His motivations lacked any gravitas. He will easily be forgotten.
The CGI. I was very surprised by how bad it was, as a whole. I don't think it happened on Snyder's watch, either. If he is good at one thing, it is visuals. Cyborg looked okay in a couple scenes, and then like complete trash in other scenes. Steppenwolf on the other hand was just god awful in every scene. There is no way those effects were finished. Ps3 level crap. Damn. A lot of the backgrounds were bad too. The background of the cornfields, the city when the League meets the resurrected Supes, the scenes of the Flash running, the tentacles and other stuff during the final battle. Yeah, all of it was piss poor.
The narrative. I found it was very choppy, in part due to the poor editing done on this film. My biggest gripe was with the motherbox being used to revive Supes. I turned to my wife and asked "What the ****?" It made no sense whatsoever. This also robbed Supes too of having earned his coming into his more cheerful identity that we read in the comics. I mean, I was very happy to see him be "that guy", but the how was plain stupid. They had a lot of potential here, and they botched it. Too bad.
Bruce Wayne/Batman. What happened here? We had this awesome badass of a Batman in BvS, and this is what we got? I understand that he had to play well with others, but they basically castrated him here. Batman rolling on the grass whining about his knee? Um, okay... wtf? Affleck looked very different in his various scenes in and out of the cowl. His wig was distractingly bad, and he looked like a different guy I thought a couple of times. I can see why Affleck wants out of the role. He sees where this is going. And that sucks... there was a lot of potential for this Batman. One of my favorite characters from the comic book world.
Aquabro. Anything I remember about him consists of his one liners, and liking alcohol. Joss Whedon further tarnished this character. It didn't work.
The Flash. He was okay in a couple scenes, but his humor felt forced and it fell flat most of the time. He runs like an idiot. Quicksilver was far better in the X-Men movies. Damn.
In summary, I think this had a lot of potential that was sadly wasted due to a lot of reasons. I think this had the potential to be one of the best CBM's ever. Joss Whedon didn't do anything to elevate this, and it is clear that the WB execs changed a lot in this. This film did not need to be made like a Marvel film. There were things in MoS and BvS that I didn't care for, but I think Snyder got a lot right. Too bad we didn't get to see that more fully realized in this flick. I think the reception and quality of the film would have been far superior to this film that we ended up getting.
Between DC and Marvel, I am more into the DC comics. So it sucks to see this come out as anything less then great or even good. Maybe it would be for the best if this DCEU rests in peace.