I have never read The Fall of the House of Usher, so I cannot comment on references to the original.

I read Mexican Gothic last year and saw people comparing it with this one, so I was not surprised to see the similarities, or to see in the authors note that they were inspired by MG. I did however find this to be more enjoyable. It felt more streamlined and didn't drag on in any areas. I'm looking forward to reading the sequel to see where it goes.