This proved to be an excellent buy. I have had it for a few weeks now and I can't stop making beautiful modular paper models. The book is of high quality, with lots of colour photographs of the finished models (useful for the colour schemes) and step by step extremely clear diagrams. Models range from the easy to the hard, but the harder models don't present greater difficulty in my opinion, they just require lots more patience (you know what I mean if you try out one of the 120 pieces models). So the book is really suitable even for a beginner/intermediate provided you have tons of patience.
On the negative side: the book is rather short (96 pages) and perhaps there isn't such a great variety of difficult models, but there is enough to allow you exploration of your own models (particularly if you have an knowledge of uniform polyhedra).
If you love origami this will guarantee hours of fun.