As someone with a long term (amateur) interest in Egyptology I have read many books on pyramids. Some (Lehner, Edwards) are very clear, detailed descriptions of individual pyramids. Others (no names mentioned) are poor paraphrases of the better books, or just plain wacky.
Tyldesley's book is different in that it explains, fully and clearly, the reasons for the development of the pyramid as a royal tomb in Ancient Egypt. I especially liked the way she uses pyramid building as a way of looking at wider social and political developments in Old and Middle Kingdom Egypt.
Bravo!!