Goodbye to Berlin - Christopher Isherwood

The book that inspired the musical and film Cabaret, should be a great, fun read right?
Well bits of it were, and bits weren't. A fictionalised version of Isherwood's time in Berlin during the late 1920s and early 1930s, leading up to the fall of the Wiemar Republic and the Second World War, it chronicles the lives of Isherwood's friends and acquaintances, from his landlady, Sally Bowles, the Nowak and Landauer families and others he meets, in a series of short interwoven stories.
The narrator (confusingly called Christopher Isherwood, although the author assures us in his introductory note, it's a mere coincidence), seems somewhat distanced from the people around him, and observes them with a detached air, as though unwilling or unable to get too involved in their lives. He's not entirely likable, being cruel to one young woman, just for fun.
At times the book drags, the way it is set out doesn't help. Hopping from one story to another, not entirely linking them together, it reads like extracts from a longer, more involved manuscript.
He touches briefly, at times, on the political situation, but as a foreigner, it doesn't seem to have much effect on him, even when it has a great one on the people he knows. It's an odd little book, worth a quick read but perhaps not worth investing too much in.