The trailer looks like pc kitsch of the very worst imaginable order.
I just watched the trailer and it is bad. It is a flawed movie- but I can't quite put my finger on why. It is certainly better than the trailer and I think a moving movie. It builds toward the scenes that seem over the top in the trailer. Worth noting that Pitt has a real bit part. Cumberbatch and Fassbender are tow of my favorite actors and were great.
I quite like his movie Hunger- about the H blocks and eventually Sands. However, that movie was a narrative disaster (12years isnt good at this either). If you dont know subject matter and context, it is a confusing mess. A 15 minute scene between a priest and Sands would make no sense to most people. An extended scene of a warder mopping out slop of cell block wing, is a bit pretentious.