I thought it was pretty good. On one hand, the story is completely preposterous and doesn't make much sense but, on the other hand, during WWII, the Nazis did many things which didn't much made sense at all with the terrible consequences that we all know. Thus, what happens in the movie actually follow their neurotic and psychotic way of thinking. Anyway, there are a also few annoying scenes (like, for example, the confrontation between Mengele and Lieberman) but it remains a good flick thanks to the competent directing, the awesome actors which deliver top perfomances (Gregory Peck, Laurence Olivier and James Mason) and the story which was just horrifying and still rather fascinating. Definitely worth a look.