I hiked the Alpine Pass Route (APR) in August/September 2004. I relied on the first edition of this book for the hike, but I own this second edition as well, so I can vouch for it. If you are planning to walk the APR, you should definitely buy this. The APR is covered in Lonely Planet's "Walking in Switzerland" as well, but Kev's book does a better job of giving you a feel for how the route meshes together as a whole. That said, the Lonely Planet book is worth a look, but consider borrowing it from your library and writing down the most useful bits in your travel notebook. You DO carry a travel notebook, right?
Kev describes the route in its entirety, and in splendid detail. By necessity, he cannot document every little twist, turn, and rise of the path, but you really wouldn't want him to spoil all the fun. His sidebar anecdotes (which I assume he must have extracted from HIS travel notebook) add a good dose of humor and personality to the material.
One thing I absolutely love about this author is his ability to put an optimistic, positive spin on every aspect of the walk. If you choose to hike the APR, the Hohtürli is probably the most physically demanding section, and Kev tempers it by reminding you that with every step, you are gaining valuable elevation. Such is the character of this book.
So, should you decide the APR is for you, buy this book well in advance, read it cover to cover at least twice, and carry it with you on the walk. You'll have a great time. Not many people get to see Switzerland this way, and for those who enjoy the mountains, this hike really cannot be beat.