This book is an excellent addition to any campain and a must for every magic-user. It fills the gaps in the rules that were left open in the SR3 rule book, adapting the advanced magic rules to SR3 level. The book has a very clear and straightforward layout allowing the reader to find things quickly. The index is also useful and the images fit into the book very well.
One of the things I am missing are some tables giving an overview over the more complicated procedures described in the book. The other thing is that FASA should have included the basic rules in the supplement, so swapping books could be minimized (this was done well in the German version).
All in all the book is very well made and the rules described are logically consistent and will fit well into any existing campaign. If you play a magician or a shaman, this will be a very good investment. (To say nothing of the other things you will be able to play if you have the book)