Not really a big fan of divorce films like this, though this one stands out with believability and very minute sentimentalism thanks to the actors and the steady direction. The ending came as sort of a shock - it is an Alan Parker film after all - but all in all it felt like it could've gathered more in its characters' lives, and not with the contrivances you see in the more generic modes of this type of story.
Outstanding performances by all cast members: Finney, Keaton, and the kids.
It has a non-formulaic feel while maintaining a lot of momentum. You don't know when the movie is going to end, but you know you're going forward. That said, I think the story is tighter than Faces, but close to being on par with A Woman Under the Influence.