It's difficult to compile a rating because any opinion of the book is probably more subjective than usual. It's not an easy or even enjoyable read. I would say it's interesting and needs one to persevere. There is a theme, even a story. The writing style must have been extremely difficult to create and maintain. The book has to be read by anyone interested in literature to round out their knowledge.
For anyone who has been fascinated by Finnegans Wake but has been unable to follow it very far in a printed version, this is a great alternative. I got a much better idea of what was going on and found it very enjoyable. The language flows like music. Of course I'm not Irish nor a Joyce expert and no doubt some will quibble about the interpretation, for example the inflections of speech which impart meaning to the stream of consciousness text - I myself doubt if there any 'right answers' to be found. However, if you're looking for a way into this book, this reading is probably as good as you're going to get.