I found this movie to be engaging, interesting and well paced throughout. Although it's a fairly straightforward storyline lacking major surprises, there is enough plot activity and character development happening to keep you wondering what might happen next.
You can probably guess the ending, and I won't spoil it. But I think the more important thing is that a movie like this, based on historical context, took such a long time to be made. In theory, this story from early 1900s could have been made in 1948 or 1967 or another random year, but the theme is so taboo, not only for audiences, but for the actors, studios (etc) that it was not possible to make this film much sooner. Apparently it had a long lasting cultural impact in Mexico, even though the "scandal" occurred over a hundred years ago.
The acting is strong. The pain each character displays is palpable. One can't help but feel sorry for the protagonist and his long-suffering wife, both of whom are equally confused, angry and fearful. They are on the opposite sides of the same coin. Both display moments of strength and courage while dealing with their pain.
The theme of being closeted, publicly outed, and humiliated happens today, in big and small ways, all over the world. While one does not need to have an "activist" mindset to appreciate this movie, the pain displayed and sense of unfairness (for everyone) will likely stir emotion in most viewers! I don't necessarily mean tears, I mean it forces one to think about ones own feelings about this topic. Maybe that was the point of the movie.