With the CISSP exam now being ONLY on the new 2021 version, I have some suggestions on old books vs. new books.
The CISSP OSG (Sybex Official Study Guide) is not out until late May (it was pushed once already), and the CISSP AIO (All-In-One) is out in October 2021.
If you are testing:
In May/June I would probably just stick with the 2018 versions, and Google the new topics.
In July/November I would get the new OSG.
In November 2021 or later, I would get OSG and/or AIO.
If you are in a country where Amazon does not ship to, please share where you can get the books, so that others in your country can get them too.
CISSP OSG: https://amzn.to/3fbs8N6
CISSP AIO: https://amzn.to/3br13ok
Other books like Luke Ahmed’s or Wentz Wu’s are still very 2021 relevant since they are not on specific curriculum but more about getting into the right mindset and perspective.