This guidebook suggests some really nice and varied tours for just about every taste and skill level. The tours are well described, thus easy to find, map sections illustrate the path (but please don't go without compass and a good map).
What I really like is the detailed and realistic description of the anticipated difficulties, but also highlights. It does not always stick to the official trails. But if "pathless moorlands, requiring good navigation skills" or "after wrestling with the boulders ..." are alluded to, you just know beforehand and can consider whether you want to make the current tour in the current general weather situation. And when good, firm and dry ground is stated, it is correct and you can safely go off according to (at least without fear of sinking in the bog or on the way to take an involuntary bath ;-)) Additional, on top of each tour description there are detailed information about distances, height gains and terrain conditions. Thus, this guidebook doesn't give a "traffic light" evaluation, as I saw it in several tour descriptions, but an honest description of the basic parameters, and then you can assess themselves accordingly to your own skills and experience.
The book also provides background information (but without intention to replace a history book) about the places and objects of interest as well as information on refreshments, also good general information on public and private transport. A small Gaelic-English glossary and a proper collection of links complete the guidebook.
Another plus is the small and handy size, ideal to take with you on the tours.
Overall, therefore, an all-round guidebook to be highly recommended for those who want to discover and explore the beautiful island of Arran :-)