This film obviously has its flaws. Weak acting (particularly from the father, George Segal) and some holes left in the plot. But it does do a great job of creating a very bleak and gritty ambiance, which I think should be acknowledged.
I agree. Segal was the weakest link in this chain, seconded by Pays, but the atmosphere was realistic and the sets authentic. I thought it was well done genrally. For me, it also had a lot of the same elements of "Summer of My German Soldier," about a Jewish girl in the United States hiding a German POW soldier, combined with a bit of "Somewhere in Time."
I would have been a mite more satisfied if Frau Hoffman had eventually given us the full story of Christa, but I guess we have to settle for the ending as dangling as it is.