This book belongs in the pantheon of well written, well presented expertise. If you liked Bringhurst's gem of a book, add this one to your library. The organization, writing and examples are exemplary. Felici's sense of humor is a treat. His sense of fit a balm to the weary.
If you are type & text junkie this will soothe your jones. If you care about type this will make it clearer. Even if you are an oldster with plenty of practice this book will add something to your arsenal. At the very least you will find how to explain all that H&J arcania more clearly to others.
And, as a last thought, I appreciate the restraint in the design of the book. It serves the subject well.