I would say to go to the building and talk to people coming in and out. If it is not a doorman building, perhaps hang out in the lobby and talk to people. Ask them how they like living there. Tell them you are considering moving there and would appreciate their input. New Yorkers are not shy about sharing their opinions! I can say that, I'm a native New Yorker.
Pick a sunny, warm Saturday afternoon to walk around the complex. Ask people coming out of the building or hanging around a local park. Talk to local shop owners near the complex and see what they have to say. It requires a little leg work, but hey, you might make a friend or two!