I couldn't get behind this book as much I could with Pride and Prejudice (which I loved), and that probably has to do with the simple reason that I couldn't get behind the main couples of the novel. Elinor and Edward were fine as a couple, though the reader never directly saw why they liked each other so much, one was only told they did and had to simply accept it as fact.
My main gripe with the story was the promotion of Marianne and Colonel Brandon as being a great match – by all other characters around them and the narrator themselves – and their subsequent (and sudden) marriage at the end of the novel. Setting aside the problematic age difference, we only ever get reference to Colonel Brandon liking Marianne, while Marianne never displays any sort preference for him in return. Not even when we're informed of their marriage, can we truly believe she has married him because of any romantic inclination on her part. Throughout the novel these two barely interact, and while Colonel Brandon does do much for Marianne because of his affections for her, that in the end isn't reason enough, or at least it shouldn't be, for Marianne's sudden return of his feelings, which seems very far-fetched knowing her disinterest in him throughout the novel. In the end, Marianne's marriage to Colonel Brandon is framed as a sort of "gift for him" for all the troubles he has had to endure in his life. Because who cares if Marianne has never shown a speck of interest in him, the poor man has been through so much, so he now deserves a pretty wife half his age that can take care of him and his estate. Austen does say Marianne had found happiness in their marriage but how can one truly believe that with what we know of Marianne's character?
Both "happy endings" of the sisters to me feel incredibly contrived, like Austen needed to end the book by the sisters marrying to their respective matches to adhere to the status quo, forced it to happen and then framed it as a happy ending for all regardless of how little sense it made in some respects.