I think this book is great. It provides a very readable history and talks about the high level ideas behind the proofs. It nicely provides short boxes that clarify details in the story.

For those who want to understand the mathematics in more detail, it provides additional information in appendices. It also includes an English translation of Niels Abel's 6 page paper that established his famous proof.

The discussion on Paolo Ruffini and Francois Viete are especially worthwhile. There's information here that's not generally well known.

This book is a model of how a math book should be written. I am very glad to highly recommend this book. Most of the books on this topic focus primarily on Evariste Galois so it's very nice to see Niels Abel also get his due. :-)