Maybe it's due to the fact that I don't see many new movies that excite me that much anymore (I certainly have no patiente at all for big-budget CGI filled blockbusters at this point in my life, and I find that a lot of more dramatic movies are turning into big TV episodes with unimaginative staging) that I found this studio production with very little dialogue that mostly relies on visuals and its actor's expressions rather than words to be quite refreshing. People in the theater were into it, it was a collective experience, everybody shut the fuck up and watched the movie.
But as for the movie itself, I liked it a lot in the way I like the maligned stage Shyamalan movies (from Signs to The Happening) - they start with this very specific idea, and stay with it until the end, not really giving a fuck about real world logic, they just want to explore their own universe. And to me, there were very few cinematically satisfying scenes as that sequence right at the beginning, or especially the one at the bathtub. I'd say that it's a lot easier for me to understand PTA's love of this than it is to understand his love for the latest Nolan and Star Wars films for example.