Crimson Peak is not a horror movie! Crimson Peak is not a horror movie, but a Gothic romance! Don't be expecting huge jump scares, gore and screams. What it has in spades is atmosphere and general creepiness through out the movie. However... The movie is dumb! Be warned! Even having a passing familiarity with the genre, you'll be able to tell the entire plot the first act! And it will play out exactly as you'd expect! The movie is slow and it feels staggeringly dull since you know everything that will happen.
Visually stunning - yes! Great performance - yes! Terrific period piece - yes! Scary - no! Interesting - no! Novel - no!
I have great respect for del Toro as a filmmaker, and this is obviously a passion project, but unless you're a fan of him or the genre you'd better avoid it! Or at least approach with appropriate expectations!