We got this guide book specifically because I wanted to get off the beaten track and see parts of Zakynthos that we otherwise wouldn't see on a first visit. And the book did not disappoint. There was a lot of useful information throughout, and I particularly enjoyed finding the natural bitumen pools (I'd never realised such a thing existed beforehand!) at Lake Keri.
On the downside, some of the walking instructions are a bit vague, and I imagine it could be quite frustrating if you were really keen to do all the walks. The couple I did were clear enough that the instructions in the book were quite sufficient for my needs.
On the upside, the little 3D sketch maps that accompany each walk, and the very detailed fold-out map at the back of the book, are worth the cover price on their own.
A very helpful guidebook, which I would thoroughly recommend to anyone who wants to get away from the main tourist trail.