"The Maid" is tense, but also a bit humorous. The first half of the movie or so is almost uncomfortable to watch at times, which makes it very effective. I like the direction it took after a third maid, Lucy, arrives.
So, the casting and acting is spot-on, the story is interesting, even if it is uncomfortable. Nothing terrible happens, though. There is a good amount of nudity involved, some sexuality, and language. It's in Spanish, so you have to read the subtitles, which are small-ish and white (they shouldn't be white!)
My grade: B+