I enjoyed it. It's a little dark in some parts and surprisingly silly and lighthearted in others. I thought Bradley Cooper did a very good job portraying a bi-polar personality, delusions and psycho-babble and all. My sister has been diagnosed, at various times, as bi-polar and narcissistic, and I totally recognized the behaviors. But it also deals with the main character's Dad, an OCD sports fanatic. So there's humor, sports fans, dancing, grieving, mental illness, family issues, love, infidelity, and how to move on from loss.
But I am very partial to Bradley Cooper, so I might be a bit biased.