I've read enough reviews stating things like 'no one to root for' and that the film is slow. I basically view both types of opinions on this film as coming from those that are the type of audiences that enjoy the endless Marvel/Star Wars drivel; where the action and pace is non-stop and unnatural and where cliche characters are everyone's favorite.
This film has solid natural pacing, and it is slow yet befitting the theme, so those that have an attention span and are in the right mood for such a film should give it a go. The film, as the synopsis says, is about a divorcee (Mendelsohn) that feels lost after the end of his marriage and abandoning his career - as most people would. Married to this sense of aimlessness is poor decisions which ultimately lead to a sort of redemption with those that ultimately matter. Mendelsohn is great as always and the supporting cast is solid. Avoids usual structure of films that many are unfortunately acclimated to that result in a firework worthy crescendo. A film about a man's life that is upside down in this regard isn't an edge of your seat film, complete with heroes and action scenes; some people really need to take the thirty seconds to read a synopsis and think (if possible) for another thirty seconds if that film is up their alley.
Bottom line: Solid movie, slower pace yet befitting of themes involved, and solid performances. Soundtrack is a dud. Those that did enjoy the movie and are readers should check out the book that preceded it.