Obviously it seems many people really enjoyed this movie, and that's wonderful. It is certainly a very well-intentioned film, and I appreciate that in an era of heartless or emotionally damaging films. Unfortunately, the film has a lot of problems and it was not something I enjoyed watching.
The primary problem is the writing. It is just not very funny. When something tries to be snappy or witty and fails, that is far worse than when it hasn't attempted wit at all. This film is to a great degree a series of "snappy"-but-gentle come-backs between adult family members, none of which seem imaginative or apt. There is also a few central premises in the film that seem like too much of a stretch of coincidence or character motivation to be believable or really work. Some of the back story seemed more intriguing, and did serve to decorate the story around the edges fairly well, but it couldn't make up for the moment-to-moment flatness that pervaded almost all of the movie.
The directing/editing doesn't support the film well, either, although I don't know to explain how exactly. Somehow things always seemed to me rather fake, and that the actors were forcing there way through unnatural material for the most part. They tried, and I don't fault any one person here. There were also too many small and charmless roles in it outside the immediate family.
Not a good rental in my opinion, though, again, apparently a number of people found it very charming (I am 38; I suspect that perhaps people over 60 might enjoy this film more?).