I think this book actually works really well as a popular science book, for those that want to learn about modern (i.e. quantum) physics but don't want the math in the way. It's a pretty good read.
But I'm trying to evaluate it as a textbook, because that's how it's conceived. The early chapters about mechanics, setting up the basics, aren't that great. They're heavy with biography, but not much else that's new. They just need to make some definitions.
Most of the book is about 1905 onward. Relativity (special and general) are first. He does a pretty good job with these ideas. Then on to quantum and particle physics. His explanations of these ideas are exemplary. Really great. You can tell that that's what he loves. Then there's an add-on chapter about cosmology and astronomy and it's, well, okay.
So a course based on this book would be in danger of being more of a history of science class than a real science class, more biography than ideas, in most areas except quantum and particle physics. But man, he does that part well. So the course would really be an "ideas of modern physics" course. That's not bad. But it's not as extensive as it's billed, and most importantly, it's not quite constructed well for that. He ended up with that focus, but I feel like he wasn't trying to do that. So it feels a little wrong. But not terrible. Mmph. It just could have been better.