I'll start by saying I give this movie a 7.5/10.
I was genuinely surprised when I saw all the negative reviews, but I do see where they are coming from, and of course the subtle undertones of the movie go over the head of people who aren't familiar with the Grindlewald and Dumbledore subplot in the books.
The overall plot; the story that is taking 5 movies to be told, moves forward about as far as it does in the first movie, but without its own self-confined plot to carry it forward. However, to give this movie a 6/10 or less for this reason alone seems harsh. The world building, character development, and backstory was deep and interesting enough (for me at least) to keep me immersed for the entire film, and I've seen it twice already. Some scenes only make sense the second time you've seen the movie, and I'm inclined to say this doesn't pull off being 'clever' film-making like some films manage. Some transitions are confusing, some dialogue isn't very clear, and it doesn't *quite* have the same charm of the first film (only just!), but that's the end of my criticisms to the film.
From a technical point of view, the CG, score and acting are all phenomenal. Camera is in one or two scenes distractingly shaky but great aside from that.
Overall, the movie is fun, immersive and an emotional roller-coaster I loved riding, both times watching the film. I've discussed this with the ~8 friends I saw the movie with, all with varying levels of Harry Potter background and they all agreed the movie was at least enjoyable. The movie was good, and I am only slightly hesitant in calling the movie "great".