I know this is a classic of the haunted house genre, and sort of last gasp of the semi-gothic novel. Not to mention Shirley Jackson being considered a giant in the field. Maybe my expectations were too high. Maybe I was expecting something different. But this just didn't do it for me. I found it a bit plodding, and hard to get through.
If you're a big fan of the gothic, this will probably be right up your alley and you should definitely read it, though I don't feel it fits in well with weird fiction despite it often being recommended in those circles. If you more plot, more action, and less atmosphere, skip this in favor of something more like Hell House.