As a warning to anyone wishing to see this movie: it is not a COMEDY nor was it designed to be. Jake Johnson usually plays comedic roles but do not expect any big laughs from him or the cast. This movie is essentially a new take on a classic relationship quagmire - 2 adults who are doomed to remain friends despite a strong sexual attraction towards each other.
The films strongest point is the portrayal of realism in regards to adult relationships. You won't find any cheesy romantic quips or witty comedic banter - just adults trying their best to deal with the problems of love and life. A large portion of the film may seem uneventful but for anyone who has been in this type of situation before, you will establish a greater connection to the lovelorned co-stars.
Olivia Wilde is surprisingly genuine and in-depth along with Johnson. Jason Sudeikis has a wasted cameo (probably decided to be in the film to keep tabs on his new wifey, Olivia). Other then that, no one else really stands out.
It is best to come into this film with the realization that it is not a comedy; that way you will have a greater appreciation of the adult themes laid out.