It is the most fluent and polished of all Bulgakov novels, though unfinished; judging by the reviews of the english speakers, the translation apparently lost that virtue.
About its being 'critical of Stanislavsky'. This is simply not the point, although I can understand the English reader, who tries to find some known landmarks. Of course Bulgakov ironizing on behalf of the actors, their ethiquette and life in the theatre, but this just serves to depict the theatre charm.As the description of the golden horse on the empty scene which Maksudov sees when he first enters the building of the Independent Theatre.
The novel itself is quite hard to understand; I believe it could be best understood by those who have a good deal of knowledge about the situation Bulgakov is describing. I cannot say I have that, therefore it is not as easy to read this novel as it is to read other works by Bulgakov. However, the novel is definitely a masterpiece - the descriptions, for example, are overwhelmingly vivid and warm, which stands out even more considering that most modern (and pre-modern) novels do not depict that warmth and depth of feeling. The strikingly accurate descriptions of human emotions seem to be a thing that can most often be found in good Russian literature (Bulgakov, Dostoevsky, Chekhov...), and that's why you need Bulgakov to use almost half-a-page to list different kinds of people, for example...
The plot of the novel is quite hard to follow - which only illustrates how much of a genius Bulgakov is, as he manages to brilliantly reveal the confusion Maxudov experiences and the absurdity of his world. The feeling of uncertainty never leaves Maxudov. Nor does it leave the reader...
I'd have given this book 5 stars if Bulgakov hadn't also written 'The Master And Margarita'. 'The Theatre Novel' is a great book, but it simply cannot be as great as that one...