I didn't think much of this. First, I was bored much of the time. Lots of courtroom scenes, without much drama. I never really engaged with any of the characters or their dilemmas, in so far as they had any.
But mainly I think the effort to restore Nazi-looted art to its owners leaves me cold. Valuable paintings are a form of money. That Manet or Van Gogh isn't worth squillions because that is its intrinsic value, but because it’s scarce and monetary value can be attached to it. So everyone who owns a valuable painting is by definition part of the super-rich.
In this story the happy ending is that the Klimpt paintings are transferred from a public gallery in Vienna to a privately owned gallery in New York, where they are on public display. The heroine realises that the return of the paintings doesn't resolve her sense of loss of world and family, her guilt at fleeing and leaving her parents behind – she still has to live with that. Well, guess what? Other holocaust victims have to live with that too, only they weren't ever rich, so they didn't either have to deal with losing their valuable art, or have any prospect of getting it back.
And a small quibble. In the apartment, at Maria’ wedding (and what sort of name is that for a Jewish girl anyway?) the exquisitely bourgeois Viennese Jews dance a hora. Would they have, or is this just the film trying to connect them with the European Jewish world as imagined by an American audience?