I find it a bit frustrating when people shit all over Mother of Tears. If you bear in mind, that it had a FAR lower budget (and shooting schedule) than Suspiria or Inferno, you should definitely cut it some slack. It's pretty darn good for such a lower budgeted film. And even the harshest critic should respect the very lengthy one-take Asia Argento investigation of the Mater Lachrymarum lair. I can also say this, the obelisk method of despatch of the main villain makes quite the impression on the big screen. Unfortunately it doesn't have anywhere near the same impact at home, it looses something. It's a film that I would always defend. Plus it's difficult to attack any horror film that pretty much opens with a character being strangled with their own intestines.
Edit: Sorry for finale spoilers, hopefully most have seen it by now...