I wrote earlier here that after seeing it in the theater I enjoyed it, and admired it technically, but I didn't think it was great.
My wife and I just saw it on dvd and we both liked it much better. It is quite dense, and it came together better for us on the 2nd viewing. I'm planning to see it again.
It is quite a daring movie by H-wood standards and quite entertaining, IMO.
I still think last year was a weak year for movies, and that Birdman was probably the best of the lot. Weak praise perhaps, but worth seeing in any case if for no other reason than to see the quality of the construction and craftsmanship on display- writing, acting, direction and cinematography.
And worth a second viewing, IMO.