Gave this a spin last night. As has been mentioned above, visually beautiful and arresting. Production design, unsurprisingly, was phenomenal. I don't doubt we saw nearly every penny onscreen. Sound design was also superb.
I think comparisons - yes, negative ones, - with Pacific Rim are very, very apt. Paper thin story with no weight or heft. Supporting characters that are far more interesting than the leads. Poorly cast lead role. Crimson Peak also seemed to have even more BECAUSE MOOBIE stuff going on, and as mentioned upthread, a lot of weirdly dropped balls (the house not collapsing on itself, the climactic battle taking place near the digging machines...just so the lead can find a shovel?).
Worse, there was zero heat/chemistry between Hiddleston and Mia W. None. I had no investment whatsoever in that relationship. Mia W was really the weak link here; we needed a lead to offer something in contrast to Chastain's strong, scenery-eating performance and we get a super bland and generic plucky young white girl.
Because the "twists" were so easy to guess ahead of time (and when I can guess them, that means the movie ain't even trying because I'm horrible at this stuff), the film really needed to deliver on the character front and it failed miserably. When the best/most interesting character in your film is the villainous, murdering incestuous sister, it's time for another few passes at the script.
It's almost hard to believe this is from the same director as Pan's Labyrinth and The Devil's Backbone. Those were disturbing, scary films layered with theme and meaning, with compelling characters and emotional stakes. This...this was forgettable production design eye candy.