I live on the edge of Dartmoor, and walk there lots.
I have several guides to walks on Dartmoor, and this is the best of the bunch (so far). It is fairly up to date (of course most of the ancient and prehistoric features of the moor aren't chnaging particularly fast!) containing details of places to have a drink, park, transport links,etc.
The colour OS map extracts are great for PLANNING and getting an OVERVIEW of where to walk. It should go without saying, if you intend to actually leave the car park and move beyond the honey pots - The Dartmoor OS map and compass are essential.
Lots af really interesting stuff in the long introduction re archeology, geology, local history, etc.
I never really go out to follow a route, and never take guide books with me to the moor. This book is better than most if like me you want to gain snippets of information and specific details for planning where I am going to go on long walks. Its list of walks is well organized, and the sections are organized in such a way that you can combine/edit/lenghten or shorten your routes to plan your own day on the Moor.
Nothing bad at all to report about this book really. All the walks are a bit too short for my day. If your looking for a short walk, you'll easily find some great routes of a few hours or a few miles. If your looking to plan a whole day of walking, you'll just as easily find stuff here to help you plan your route(s).