Normally I'd say German productions are so uninspired nowadays, something something Nazis...aren't we bored of Nazis yet? It's all a far cry from the creative 70's/80's heydey of the likes of Wenders, Fassbinder & Herzog, where the subject matter was wide-ranging and original.
But at least this puts a twist on it by being set in the roaring 20's, where I'd hope the Nazi angle to be a side-plot rather than the main focus. Here in Berlin I've been to a few 20's-themed parties, that decade is a favourite here (much like how the 60's are seen in England...a period of revolution, creativity and hedonism).