I can't deny that the story gets a little predictable along the way, but it was still really very enjoyable. Also, the movie gets points for its soundtrack; I love romantic comedies that use standards and jazzy tunes.
One of the best things about this film is how the kid is portrayed: as an individual, with a father who treats him as such, and they discuss sex. Apart from that, there are a few good gags (one being all the 1990s styling) but it is very 2D.
It's pretty low key and relies heavily on what Ephron thinks is witty and clever writing. Sometimes she misses, sometimes she doesn't. The self-awareness of the whole thing gives some very pleasant moments, and the ending is great.