I just got this movie for my sister for Christmas, and we saw it with my older sister and Grandmother. My Grandmother, by the way, happened to have worked at a mental institute as well, and she thought everything about the movie was really doopey and over the top. She kept saying that the actors felt like they were reading their lines, and she even admits to not being a big fan of Martin Scorsese movies anyway.
As for me, I thought it was alright. I honestly didn't see the twist ending coming, thought then again, I haven't really seen a lot of movies like this, so whatever.