We went to the 3:30 showing on Sunday. That (crowded) audience didn't make a single sound for the entire film! It was that engrossing, but, as Denzel Washington said on some interview I saw, "The stuff in the preview isn't what it's about." It's not. The rest of the story is triggered by the crash.
It's really an exploration of rock bottom.
Not entirely realistic, but easy to have empathy for the character played by Denzel, and in the end, it depressed me. I'm not sure why.