I finally saw this... and I wish I hadn't. It was pretty bad. Mostly nonstop action without a lot of characterization. It had a few nice moments, but they were outnumbered by the weak or stupid moments.
Superman, who should be the heart of the team, was barely even there as a character, just a big dumb overconfident lug who punched things and flirted with Diana. Wonder Woman herself was far worse, a caricature who claimed to be a "warrior" but was shallow, impulsive, and reckless without a trace of discipline. Come on, no "warrior" is going to casually swing her sword around and point it at people merely as a form of address. A warrior would have more respect for her weapon and its danger.
Didn't think much of how the other characters were handled either, but the worst was probably Darkseid. He's supposed to be a monarch, a commanding figure who rarely needs to dirty his hands with actual combat because he has so many underlings to do it for him. The threat he poses is generally more psychological, in the way he manipulates and corrupts and bends people to his will. So when he does strike physically, it has a real impact from a story point of view. But this Darkseid was a barely literate, grunting thug. They pretty much turned him into Doomsday, a threat that's all brute force and no personality or intelligence. I wondered why they even bothered to call him Darkseid.
Some of the voices were fairly good, but they didn't have much to work with. Even Alan Tudyk wasn't all that much of a standout, since he was given such a shallow, one-note Superman to portray. The one real standout was Marjorie Monaghan as Wonder Woman, who stood out for how terrible she was -- although I think the blame there lies more with how the character was written.
If this is going to be the DCU movies' primary continuity from now on, I'm not optimistic about what lies ahead.