Hard to know how to rate this, I've been an avid user of Sunflower guides for years, my only complaint is that they tend to try and cover a too large a geographic area, and this one is the granddaddy of them all. From the Atlantic to the Mediterranean in 34 walks covering over 400km of mountains means the walks are spread a bit thin over the ground, so I think where this guide shines best is on a car tour along the length of the Pyrenees allowing you to sample the wonderful walks along the way. However if your holiday is going to be more centre specific then it is probably less useful and I would suggest you would be better off with one of the many guides concentrating on your particular area .
That said, the information, route descriptions, maps and insight are, as ever, up to their usual perfect standards.