but not very inspiring.
Yes it is in French, but assuming you can read French the Green Guides are the "standard", and their use of the language is pretty straightforward. Many are also available in English too.
They are well organised, contain useful information on all sorts of places from small hamlets to big cities, are accurate (or were at time of going to press I guess - prices/times change) with admission charges and opening times, and contain suggested sightseeing tours of various durations as well as descriptions of those sights. But they do tend to be a bit dry and contain almost no photos.
There are plenty of other guide books out there that contain fantastic photos together with lots of descriptive text, but little or none of the practical information that the Green Guides have.
The Poitou Vendée Charentes guide is no exception.
I do like their rating system: "Worth a special journey", "Worth a detour", and "Interesting".