Many of the names of the teams and the villains will be familiar to longtime Champions players. There are new villains and teams here too and all of them are updated to Sixth edition rules.
From a resource standpoint, this is a great book. You can quickly grab a team to make them part of your next adventure. There are plenty of teams, themes and power levels to make it work. You can also pick out an individual villain if you need one.
The other thing the book is good for is providing examples of a lot of different villains and powers as well as of different teams. It makes it obvious that teams can come together for a wide variety of reasons and stay together for even more.
This book isn't well-suited for non-champions GMs as there are a lot of villains and a lot of character sheets. This means a lot of conversion if you'd like to use these characters somewhere else.
For Champions GMs this is a great book but it would be a lot of effort to convert it to a different system.