Saw the film in theatres last night, there were so many plot changes and there's a second part coming out in September. I'd give it a 3/5, given the budget they had you could tell they put their backs into making the film good. There are some major plot changes, but as far as live action anime films go it's not bad.
@Sunnycanary613, @Ashia J all I can say is beware huge plot changes, and don't expect ALL of your favourite characters to be in it. Especially Levi, they replaced him with a random character who's also a titan killer but has a worse personality.