For the most part the Player's Guide is just selected excerpts taken directly from the Core book, so there really isn't anything new if you've already picked up the Numenera rulebook.
What you do get however is a well-selected cross-section of the information that players need to give them a basic understanding of the rules, the setting, and the characters they are creating, all interspersed with a great selection of the artwork.
I'm much happier giving new, and even experienced, players this book with only 64 pages of specifically selected content, over letting them try to figure out what is useful and what is not from the Core book which weighs in at over 400 pages.
The only things I really feel could have made this book more useful are the addition of sidebar annotations & hyperlinks as in the Core book, and to transplant the character creation walkthrough from the Core book to the end of this book as it would feel much more "at home" here.
[4 of 5 Stars!]