"Justice League" is a fine movie. It's not world changing, but it's fine. A solid two hour film that's fun to watch. As far as the DCEU films go, this is maybe my second favorite one; "Batman V Superman" isn't as good as "Justice League", but "Justice League" isn't as interesting as "Batman V Superman". Take that as you will.
I have no major complaints I guess aside that I thought Superman's CGI upper-lip was a bit distracting. But yeah. A definite improvement. Maybe one or two too many jokes in it from characters who shouldn't be jokey, but that's it.