I couldn't put this book down. Some of the mathematics and measurements were a little hard to follow, but essentially it was excellent research on the part of Ralph Ellis. I have confirmed much of this for myself now (as everyone should do after reading any book) and can accept much of what he says.
The Stonehenge, and avebury sections were excellent and possible (if not probable). I was looking forward to hearing more about his story on the pyramids, but found his conclusion here a little disappointing. I don't want to waste it for anyone else, so let me know what you think after reading it. Perhaps I am being a little harsh on this section of the book.
All in all, well worth the money.