I don't know the film, BobbyZ, but I did see the play by Ronald Harwood on which it is based. The latter was notable for a superb performance by Daniel Massey as Furtwangler; he was seriously ill at the time and died not long afterwards. I have a suspicion that his performance may have made the play seem better than it was but that may be unfair. Thanks for the heads up on the film. I shall make a point of watching.   

I would give quite a high recommendation to this film. (I've never seen the play though.) The most important aspect of it for me is that it admits of no easy conclusions on the part of the viewer, with the implication that there are no easy conclusions so that when trying to think realistically about Furtwängler and his work (or that of Richard Strauss, Wagner, Shostakovich...) in relation to political events and realities, it's necessary to keep all the contradictions as contradictions, and not try to resolve them into clear black/white terms.

I saw the play on its pre-London tour, back in 1995: Michael Pennington played the army interrogator and Daniel Massey was, indeed, supernaturally superb as Furtwangler.  I say that because, on his first appearance, I was stunned by how accurately Massey had contained Furtwangler's appearance and physicality.

The play is by Ronald Harwood, author of another interesting boulevard piece on Mahler, which was given a short-lived West End production in 2001, featuring Anthony Sher (one of the few occasions when I've actually enjoyed a Sher performance).  I don't think R.H. would claim to be in the business of creating great drama, but these two plays are interesting, 'commercial' works, which have the added benefit of providing roles for star actors. And nothing wrong with that.