The most recent review, a rather thoughtful piece on amazon.com, called it "excellent" - though they did have a few complaints: "The Kino Blu-ray comes with an excellent full-length audio commentary by Thomas Gladysz, the director of the Louise Brooks Society, which is an online info archive devoted to Brooks. Unfortunately, there are many long stretches of silence during the commentary. Gladysz talks about the actors and crew, the film's artistry, the historical background, and the social climate at the time the movie was made. At one point, he recommends that we check out a documentary on the life of one of the minor actors in the movie, Kurt Gerron (who plays the portly, friendly figure of the brothel), but didn't mention the title of the documentary. That film is the 2002 Oscar-nominated feature documentary "Prisoner of Paradise", about Gerron's life and career that were cut short by the Nazis."
I stand corrected. And I am truly glad that attention has been called to this outstanding actor and personality. Here is that documentary, which includes a clip from Diary of a Lost Girl.