Borrowing some Marvel Magic, Justice League is a homerun for DC.

Rating: 6/10 (19 November 2017)

To address the Marvel V DC issue, my perspective is that Marvel has always been consistently very good, but DC has had higher highs and lower lows (within the films and across the franchise).
Justice League is one long high, cinematically speaking.
The film has all the best hallmarks of Zack Snyder -- the cinematography, the symbolism, the action, but it's been tidied up with some of Joss Whedon's little humor moments, and although I'm not at all a Joss fanboy, I think the marriage of the two filmmakers' styles does the film...justice.
The ensemble comes together a little hastily in this story, which has been DC's main weak link until now, but considering how Warner Bros. has not allowed the series the time to flesh each character out before joining up, they newcomers (Aquaman, Flash, Cyborg) get introduced rather quickly, but it's OK because their backstories are hinted at enough to be interesting to casual filmgoers, but comic fans already know what they are about.
Steppenwolf is your typical comic movie villain -- except with Ciaran Hind's voice acting lends him a kind of stage-play gravitas that works well for the character.
A few other points: Wonder Woman continues to be a highlight of the series both visually and narratively, Snyder's Superman is ultimately badass (sorry Donner fans), Jason Momoa nails it as Aquaman, I had a hard time letting go of the CW Flash but Ezra Miller made me forget it.
To summarize, Justice League was an awesome superhero film -- one that is as good as anything Marvel has done. I only hope there will be an extended version because I suspect it would be even better than it already is.