Not nearly as bad as the reviews make it seem
I know I'm in the minority here, but I genuinely enjoyed what I saw. I think the mutants were cast about as good as they could've been and they were all compelling in their own way. My main gripe is they didn't spend more time on getting to know the mutants better.
It's not the best superhero film, but it's certainly not the worst. Definitely not the worst just among the X-men franchise either. I honestly think it's a shame it won't be trilogy like it was initially intended.