This is a tale of two movies.
I was completely engaged with the story of Sarah. The WWII and 1950's flashbacks were very gripping and kept me wanting to know more.
Julia's story on the other hand was boring and kept me wanting to get back to Sarah. The sappy ending didn't help either.
So basically this is half of an amazing movie, the other half should've been left untold. Still the good outweighs the bad, and gets a high rating.