PRO: At least Justice League isn't a grim slog like Batman v Superman: Dawn of Justice. What a drag that movie was.
CON: I'd say this film had a little lighter tone, except I don't think it could be said to have any particular tone at all. There are some funny lines, some standard superhero mopery, and clumps of character moments—meet the Flash, say hi to Cyborg—amid acres of hysterical CGI, some of it quite bad. Every now and then you also get an unexpected squirt of all-purpose syrup– something I attribute to Joss Whedon, who did some writing on the movie and later took over post-production and substantial reshoots after director Zack Snyder was sidelined by the death of his daughter last spring. Whether or not Whedon was actually responsible for the scene in which Superman and Lois Lane stand cooing at each other in a (CGI) cornfield, I feel that his presence enabled it.
PRO: It helps to have a team. With four new characters on hand – Jason Momoa's Aquaman, Ezra Miller's Flash, Ray Fisher's Cyborg, and Gal Gadot's Wonder Woman (no longer a newbie, of course) – we don't have to spend two whole hours hanging out with Ben Affleck's po-faced, chokey-voiced Batman. (Affleck is so clearly over this role that he might as well have a FOR SALE sign stenciled on his cape.)
CON: The team hasn't quite jelled yet, even with Whedon—Mr. Avengers!—on hand. Momoa's matey submariner ("My man!") and Miller's lovably frazzled speed freak are well-worked-out characters, and the prospect of their future stand-alone movies now seems promising. But the personable Fisher hasn't been able to make much of Cyborg's tragic backstory—he's a mostly metal guy with a lot on his mind, that's about it. And Wonder Woman, as you might expect, is slumming here—Gadot is so electrically alive in her every shot, she makes the other actors look as if their batteries have died.
CON: The sexy. You know Gadot's not in Patty Jenkins land anymore when you hear one character bellow "You're gorgeous!" at her, and then, in another scene, watch as the camera travels up her legs to her tightly leather-clad bottom. Meanwhile, back on the island of Themyscira, some of WW's fellow Amazons have been reintroduced to traditional hot-goddess bikini-wear. Not that I object to this sort of thing myself, but I'm told there are many who do.
CON: Nobody fears a lame supervillain. The one here—a crude digital confection called Steppenwolf—might have been designed on an Etch A Sketch screen. He growls and waves around his axe a lot, and is snarlingly concerned with three otherworldly boxes, one of which was long ago given to humans, another to Aquaman's undersea people, and a third to the Amazons. Steppenwolf's evil scheme to trigger "The Unity" (whatever) naturally requires that he find and possess all three of these boxes. I kept wishing somebody had provided him with One Box To Rule Them All, but we know how litigious the Tolkien estate can be.
CON: Nobody fears a lame supervillain's lame subsidiary villains, either: Steppenwolf is attended by a winged horde of ghoully sub-demons who resemble nothing so much as a huge swarm of flies. When they bear down on a family's home in…Iceland, I think…a little girl actually pulls out a can of insect-spray and fixes them with a menacing moppet squint. A teeny joke, I suppose, although a bit light in the laughter department.
CON: As noted above, the CGI in this movie is of a surpassing cheesiness. Every one of the many, many sky-fights, mega-booms, and fantasy landscapes on display here seems to have been purchased at an FX fire sale back in the 1980s. And the fact that there's so very, very much of this stuff makes it even worse. (Special smack on the head for whoever concocted the big purple tendril thingies that come sprouting up out of the ground so ridiculously toward the end.)
CON: Superman. Don't pretend you had no idea Superman was in this movie. So what if he died in the last one? He's back on the case, and the excessively sculpted Henry Cavill is still playing him as Jesus. I don't think Jesus put in as much shirtless time as Cavill does here, though.
CON: The dialogue. You gotta chuckle when somebody asks Ben Affleck what his superpower is and he says, "I'm rich." But then you have to groan when he gives forth with the Hollywoodian "We tend to act like the Doomsday Clock has a snooze button." And as the movie continues on toward its inevitable credits scenes, you have to keep groaning, I'm afraid.