Try to imagine what this movie is like, how it unfolds, and how it ends. Well that's exactly what it is. Predictable to its very core. On the other hand, this is a RomCom, so it's kind of to be expected (come to think of it, a RomCom where the guy doesn't get the girl would be a pretty cool idea). The basic concept is used pretty well and makes for some pretty decent jokes, but this is pretty much standard fare all around. Still, it's fun and light.
In a sentence:
Your basic, entirely mediocre and formulaic RomCom, but with a pretty cool main concept.