It's been a while since I've read this book, but I can say that it's one of the most important books I've read. It's not a book to be read for entertainment, or for a "wow" experience. And yet I certainly didn't find it dull. I don't think the book is for "overly intellectual" people. But I would say it's a book for thought and reflection, as well as for knowledge.
This book was written because, "In the modern period, we are without a comprehensive story of the universe. The historians ... deal not with the whole world but just with the human, as if the human were something separate from or an addendum to the story of the Earth and the universe. The scientists have arrived at detailed accounts of the cosmos, but have focused exclusively on the physical dimensions and have ignored the human dimension of the universe."
In their account, the authors take a mythological approach to the story of the universe, "humanizing" the various stages of its development, but also basing all that they write on the best knowledge yet uncovered by science. The deliberate, and successful, result is the growing feeling that the universe is at last telling its own story, though us. We ourselves are part of the universe. The universe evolves! It hasn't always been as it is now. This fact may appear boring to some of us, but in a broader perspective, this idea is a radically new and exciting idea -- unthinkable in times past.
Told in this way, the story is one of familiar (i.e., mythological) forces and processes interacting at each stage, but with each stage being yet more complex and intelligent than the last. The universe doesn't just change, it evolves. And as we discover its story we see how much a part of the universe we are, and that our own awareness is also a part of it.
I believe that these ideas are essential for our own human evolution, and our ability to invent our own next leap, together, into the future.