I have watched Birdman and I am very impressed with it's story, the performance of the actors and music and so on. However, we've always been told that the best cinematography is the one that doesn't draw attention to itself. I know Birdman is shot to look like one continuous for a reason. But it is not settle at all. Make no mistake, I do think Lubezki is a amazing cinematographer. Gravity is full of long takes as well but they don't seem forced to me. However, you can see they deliberately pan to hide cuts in Birdman.
My point being, Long takes are great, but it shouldn't be the only reason to win an oscar.
Just my two cents