Living in an area in the south of England which is blessed with an abundance of great roads, I wanted something that could expand my usual routes.
In reality it confirmed what I already knew, but also left out some glaring (and potentially obvious) routes which vistors to the region would be daft to miss. In addition, suggested some other to routes (A24? A23!!?) which would not be on my list of great bike rides.
To that end, this knocked my confidence in the book, and it's suggestions for routes outside of my local area.
Couple that with a hefty price tag, its difficult to recommend as a definitive guide, but may put you roughly on the right track. Just be prepared to get off the beaten track once you get to wherever you go.