Fantastic cinematography, good acting, badly written and overall frustrating.

Rating: 3/10 (30 September 2015)

I've tried to keep this spoiler-free, so the writing will seem bland and unspecific, if you would like my thoughts of specific plot points, you can read the bottom bit after reading the rest.
After hearing the mountain of hype critics have been giving this movie, I decided to watch this against my better judgment (I've been burnt by several critical darlings in the past). After an over-the-top stylish credits sequence with what I realized would be the soundtrack (a near-constant string of drum solos), I was immediately impressed by the cinematography, which for about 95% of the movie is shot and edited to look like one incredibly long take (which it isn't, but looks pretty realistic).
The lighting, framing, sweeping camera and distinct lack of cuts after the first few minutes was amazing. The story on the other hand, takes a while to get going. Although Keaton and Norton are great together on screen, I liked some of the commentary of the current state of movies and the pretense of theater as "the superior medium". I thought that they made the critic character who plays a minor role in the film way too "evil" to be interesting, but that was a fairly minor issue compared to the rest.
I didn't really connect with the story until about halfway through the movie when twists occurred and some real conflict started sparking up. That's unfortunately, when all the setup of the first two thirds of the movie devolve into a weird 3rd act where everything comes collapsing down.
After the movie's rather abrupt ending (instantly reminded me of the letdown I had when I saw The Wrestler's ending credits appear), I realized that about half the characters, plots and character arcs were simply just dropped and forgotten about around to 60-70% mark. None of the major plots or characters were tied up or referenced. No closure, no resolutions, nothing. It literally just forgot about half the story. It makes me wonder why several characters even existed.
Overall I found the movie extremely well-crafted despite dropping the "one-take" illusion about 3 times in the movie in completely weird and unnecessary parts, as well as my personal loathing of the grating drum soundtrack, which felt distracting and didn't jive with the rest of the movie for me.
Below are more specific comments which may include minor spoilers.
SPOILERS (Do not read if you are averse to spoilers): --------------
My biggest gripe with the movie is that most of the major plots and subplots -- Riggan's daughter Sam (Emma Stone, Mike (Edward Norton), Mike's relationship with Sam and Leslie (Naomi Watts), his bumpy relationship with his current girlfriend Laura and his ex Sylvia -- were left completely unresolved. Perhaps maybe one or two of these not completely tied up would be acceptable, but it seems like a complete waste of time to spend over an hour developing all of this story just to forget these characters even exist toward the end of the movie. Yes, two of the above characters were present in the final scenes, but they might as well been hospital staff for all that it mattered to their respective stories. Oh and don't get me started on the damn asteroid cuts that completely cut in and derail the entire movie and are not referenced anywhere else in the film. Overall, some cool moments and great film-making, but with badly resolved subplots and a muddled ending.