Let's start with sound. One of the most important factors about Argento's Suspiria is its radical unfront use of the music scored by the Goblins. From the first second of the movie we are enveloped by an aggressive driving force of intense music while watching an electric door open and water running down the drain. Seriously, I have never been so scared of shadows on a tree but the music does it. Guadagnino's use of Thom Yorke's lack of sound is the opposite. There are actual dance scenes where there is NO music. It is absolutely absurd. Moreover, in the final climactic scene of the murderous dance, he basically uses something a Radiohead song.
Another aspect of tension and effect was Argento's use of color where his pulled saturations created a mental dissonance and surreality. His use of Art Deco settings helped the environment become a key player in the 1977 film. This is expressed when Pat falls through the glass mosaic skylight or when Sara was trapped by a room filled with wire. The exterior of the dance hall and the blue iris painted walls all added to the character of the coven. You can't deny that Guadagnino literally ripped every aspect of color from this film making it horribly bland to even look at.
Sidebar: this film had the worst sound/dialog recording ever! Every line is delivered with a mumbled inarticulation that drove me mad and forced me to eventually disengaged from listening. Moreover, the horrible master mixing only made it worse.
Lastly, the violence in Argento's original had the critical aspect of camp that allowed the viewer room for disbelief. It is horrific, but also silly. This is also based on the period when it was made. Guadagnino's murder scenes incorporated the victim urinating on themselves and push the envelope to snuff movie levels, which is not what horror suspense is about. Conversely, The final "dance of death" was so ludicrous that I laughed out loud at the absurdity.
Lastly, the need for Tilda Swinton to play two roles was interesting as an expression of her talent but completely distracting in the movie. First off the makeup was like watching a bad version of Dustin Hoffman's elderly character in Little Big Man. I was constantly distracted by the makeup artists inability to connect the prosthetic with the actual mouth. It was a continual obvious fake for the whole movie.
I rarely ask for my money back during movies in theaters. Had this not been such an important movie for me to criticize (because I love the original) I would have.