You really show some passion for this violent, sadistic movies;-)
It's not especially for the gory set-pieces, in fact the violent, torture scenes in "Opera" are more disturbing sad and harrowing than thrilling i must say

, it's mostly for the gorgeous camerawork, widescreen cinematography, use of locations and music that the film has to be seen in theaters for the greatest effect/impact.
Gory, violent scenes in Argento's movies are a small part of the interest of his works, what is mostly captivating in his oeuvre in my opinion is his camerawork, his framing like painting, i also like very much his obsession for architecture/use of locations and the poetic tone of many of his movies and scenes, also the many "wandering" parts of his movies, when characters are walking for long minutes in streets, old houses and buildings, even in countryside (like in "Phenomena" or a few scenes of "Opera" and "Trauma")

Also, despite not being considered like a great director's actors, i think he has offered many interesting parts to his leads, especially the actresses...Jennifer Connelly, Jessica Harper, Stefania Rocca, Daria Nicolodi (in "Deep Red"), Asia Argento (in "The Stendhal Syndrome" and "Trauma"), Marta Gastini...all of them are memorable ladies in his films.
I've heard about the cut German blu ray of "Sleepless", but if i remember well the TonFilm edition Blu Ray was uncensored...i own the french and italian dvds and both are uncut.
Something I've realised... I might have never seen his version of Dracula. Yet I was sure that I had, at some point! But i have utterly no memory of it. Probably should look into that.
It's not a great film by any means, in fact it's a minor Argento movie, but it has its charms, i liked some of the nightime cinematography (the director of cinematography is Luciano "Suspiria" "Tenebre" Tovoli), the gothic old school vibe and the lead actress Marta Gastini who is a fine, charming Mina Harker. If you have to watch it, watch it in 3D, the film was shot in 3D and the 3D is used nicely in the movie.
How would you rank Argento's movies Master Ray? From the best to the worst?

I would try something like this...
My favourite for years!:
1..."Phenomena"
Very good:
"The Stendhal syndrome"
"The bird with the crystal plumage"
"Opera"
"Tenebre"
"Inferno"
"Four flies on grey velvet"
"Suspiria"
"Deep red"
"The Card Player"
Good:
"trauma"
"Cat'o'nine tails"
"Do you like Hitchcock?" (tv)
"Jenifer" (tv)
Not great but enjoyable enough/ok movies:
"Mother of tears"
"Sleepless"
"Pelts" (tv)
"The black cat" (in "Two evil eyes")
"Dracula"
"Giallo"
Ambitious but mostly failed movie despite some nice things in it...:
21..."Phantom of the opera"