I am also looking to take the Cissp-Issap exam and from your comments it seems that the book is not enough to pass the exam. Experience is essential (and we know this is true) but having the right guide is always best way to deal with any kind of questions but more important on day-to-day challenge. For example, the Edition 2 does not contain any chapter regarding Cloud Security.
If you have not already, I would recommend looking at the Exam Outline (linked here and attached to the right), this is updated with the new domains and the weights for those domains. You can also see some suggested references here that may be helpful to you when preparing for the exam.
I sent an email to EU ISC Support and a new version of the ISSAP book is expected for July 2018. Domains changed and a new guide is absolutely needed. Even if we are 100% Security Architect, a guide is always a good compare point with what we do and we could do in our work.
I am looking forward to getting the new ISSAP book.
In the meanwhile, we wait.............