As just a book, I definitely recommend it. It's earnest, compelling and thoughtfully written. I plan to try constructing the SunStar when I get the right boxes for it and then I may update my review with my assessment of it as a how-to guide. As a resource for reading about history and design it is excellent.
I had my first solar oven baked cookie at Earth Day in Balboa Park, San Diego was about fifteen years ago. The first place I returned to was the solar cookie station. Regarding solar ovens, If you leave most of them out in the elements, far away from the shadow of your home or shelter, no good. Ours disintegrated. I'm thinking about the next one, and maybe this one can be all metal and glass. I want to try the parabolic cooker, the stovetop of solar cookery, they use a concave surface to concentrate the rays into much higher temps, like 600 degrees. They require tracking adjustment every fifteen minutes but cook doubly quick, which is important you think cloud cover might be far in the horizon, and are much less to carry. If you're looking for something you can leave at home for slow cookery on a Sunny Day, the more widely available oven will be enjoyable. And safer than leaving a pot of chili on a burner all day. Heaven's Flame is more entertaining than other solar oven books, another good thing out of Ashland.