This is a beautiful book with beautiful recipes. The cakes, on the whole, are absolutely gorgeous. I cannot stress enough how they do not taste of vegetable at all, as I've sometimes found with other "healthy" cakes. My boyfriend bought me this as a present (clever fellow that he is!) and until I read the introduction neither of us realised it was a "healthy cooking" kind of book. Certainly doesn't taste like it.
Only a couple of cautions (I can't call them faults, the book is too enchanting):
I've tried two chocolate recipes so far (the chocolate and peanut butter cupcakes and chocolate chocolate chip cupcakes) and while they've been perfectly adequate little cakes, I wouldn't say I swooned with the rich chocolatiness of them. You'd have to swathe them in icing to get quite the same hit as you do from, say, some of Nigella's indulgent chocolate recipes. Having said that I am an unreconstructed lover of good old British milk-and-sugar chocolate, so it's possible these recipes are a bit subtle for my palate!
Second point (and I wish someone had told me this when I started making the cakes) is one about timing and ingredients. Harry insists you shouldn't grate the vegetables "until you are about to add them to the mixture." This is all very well, but hard vegetables like potatoes, butternut squash etc can take ten minutes to reduce to a fine shred by hand (she won't let you food process them either), by which time the eggs and sugar you've just whisked have lost a bit of their fluff.
By trial and error I've found that what Harry calls the "woody" vegetables (potatoes, carrots, parsnip, beetroot etc) can be safely grated before you start the whisking. They can cope with sitting for 5 minutes without getting damp. The so-called "water" vegetables (courgette, aubergines etc) can't cope with pre-grating, and do get very soggy (as you'd expect). They have to be grated the minute before you put them in - but on the other hand, they're softer and take far less time than the hard vegetables, so they won't hold you up with the eggs and sugar.