I have to admit I'm not Harry Potter's biggest fan. I read the first few books of the series before losing interest somewhere about the fourth one. I've seen most of the movies, I think, but not on first release or even in order.
By the same token, I don't dislike the series as such. It's fun if you don't take it too seriously, and it's that element that element of fun that I enjoyed so much in Fantastic Beasts. It's an amusing story about crazy things happening just below the surface of our world. It makes a great deal less sense than the Potter films, in that all this takes place in New York rather than the English countryside where something odd might pass without notice. But just ignore that. Go in and expect some lush visuals and an enjoyably silly mix of whimsical Englishness and stilted old-timey New York and it's a decent film.
The story puts some interesting character types front and centre. Eddie Redmayne plays Newt Scarmander as someone pretty clearly on the Autism spectrum, and his sidekick Kowalski is a tubby everyman with no special abilities. Less enjoyable is Katherine Waterson as the woefully undercharacterised female lead, fortunately balanced by Samantha Morton's Mary Lou, a flapper with psychic powers.
Actually, forget the other characters. I'd pay good money to see a film about a flapper with psychic powers. Hollywood, get onto it please.
Anyway, I did like the way that the heroes weren't all super-attractive types. But then Harry Potter has always shared that weird X-Men paradox of being about the outsider – so long the outsider has superhuman powers. Are you an outsider without special abilities? Good luck with that.
The antagonists include a sinister villain whose motives didn't make a lot of sense to me but probably mean something to people deeper into Harry Potter lore than myself. There's also a tragic villain, whose tragedy seems meant to have parallels to the life of queer people in a repressive religious family. It'd be interesting if it wasn't a part of the weird difficulty JK Rowling has with just writing a gay character directly.
Like the Potter films, there's the very clear resonance that the baddies are reminiscent of Fascists – although the 'good guys' seem pretty prone to imprisonment without trial on the basis of pretty flimsy evidence. And the way they can just mess with people's memories without permission… it's a little creepy is what I'm saying.
Anyway, bottom line, I recommend Fantastic Beasts as a good film to see at the movies or on a big screen TV. Most of the fun comes from the visuals, and there are some very cool monster designs. Look out for Ron Perlman as a goblin. It's weirdly awesome.