I just passed CE and 95% of my revision is based on Ballast. I did the same for PcM and PjM and I passed both.
I used Ballast Review Manual and Practice Exams. When I checked the forum 2 days before my CE exam, I am a bit freaked out to find not a lot of people mentioned them for this part of the ARE exam.
I have to give enough credit for the books, as they are very well organized and helpful for these 3 exams I took.
I did find several mistakes in the books, even in the answers of the prarice exam, but overall I trust their accuracy.
Congrats on passing! I'm taking my CE exam this Thursday and have been mainly reading the Brigthwood book and Contacts. I've been reading the Ballast book and doing the exam and practice questions and was feeling great until I discovered the errors! I'm stoked to hear that they worked for you.