The main weakness of the film was Julianne Moore - her acting was fine and all, but her character was a bit disappointing, a needy, melodramatic middle aged alcoholic. She's supposed to be Firth's best friend, but it's awfully difficult to understand why they ever became close in the first place, because she's mostly quite irritating. It's too bad - it would have been so easy to give her character a bit more, and at moments the movie almost seems to, but then pulls short.
Also, without giving it away, the ending had me scratching my head a bit. It's a really odd way to end the film, and I'm not entirely sure why it went the way it did. I almost thought it would've been better to end 20 minutes earlier, in a lovely scene on the beach, but then I thought well no, you probably need a bit more - in any case, it was strange.
But ultimately, a very enjoyable film, if a bit melodramatic.