The portrayal of sadomasochism / lack of consent is definitely problematic, but that flaw aside, I love this movie. The acting is incredible, and the movie is so well crafted.
Really effective pacing - his day to day life edited with quick auto-pilot snippets and his time with the dominatrix playing out in long, slow, intense scenes where he's fully present.
The final scene even warms my icy heart. A real feel-good BDSM movie.