This story line is so simplistic that it really needed something else -- anything else -- to make up for it. Sadly, that wasn't forthcoming.
This is a very "meh", vanilla British movie. The characters weren't compelling, or even interesting, really, but the acting was okay for a comedy. In fact, it was so middle-of-the-road and good-natured, I almost feel bad nitpicking about it.
I almost laughed a couple of times, but it didn't quite get there. I think someone was trying really hard to give this a "Bridgitte Jones" vibe, but it just didn't stick.
If you are looking for a light-hearted (and I mean, really lighthearted) flick to waste an hour or two, this may fit the bill. If, however, you are looking for an intricate plot, developed characters, fantastic cinematography, drama, intrigue, thrills, sex, or serious comedy, you might want to pass on this one.