The two reviewers before me seem to have missed the point entirely. Why bother to review (and, what's worse, give one star) just to say there is something wrong with the 'aspect ration', whatever that is. The other reviewer thought that the plot was weak. On the contrary, the writer overcomes a major plot problem with great finesse, and turns the whole thing into something much more problem. The problem is how to introduce the pregnant Rose into her dead lover's parents' household at a time when their grief is fresh. Normally, they would know his girlfriend as a matter of course, or he and Rose would have been living apart for some considerable time, and so weakening the parent-son and brother-brother bonds to some degree. There is a key passage in which Rose talks to Bennet's father and tells him everything about what happened between them. It seems they had been in love with each other for four years, but he only got up the courage to speak to her on the day they meet, go to bed, and are victims of a fatal car crash in which he dies. It's those four years of unspoken love that allow her to sum it up: 'He was the love of my life'. You have to take that seriously, and then perhaps to understand that her grief is the greater, in that she will never love or be loved with that intensity for the rest of her life. This is serious stuff that transforms an ordinary grief movie into something more.
Of course, neither Piers Brosnan nor Susan Sarandon is strong enough to make this work as well as it might, and the writing (despite that very fine plot resolution) simply isn't up to it. The film suffers too from the American propensity for 'redemption' at the end of novels and films. A French director might have made more of this.
But I've given it four stars to acknowledge the stellar quality of Carey Mulligan, both the most beautiful and most expressive of actresses from her generation. The Greatest, like An Education, is very much worth watching just for her performance, for her dazzling smiles, and for the European subtlety she brings to her role. Sarandon's mother is unsympathetic, Brosnan's father seems too remote until he achieves redemption in grief, but Rose ties everything together, through her own loss and her pregnancy. Don't let these one-star reviews persuade you not to buy or borrow this. It may not be the greatest film you will ever see, but, curiously enough, you may find that you never forget it, because Rose's story is so exquisitely painful.