I passed my exam today. I took the old exam. From what many people are saying the old exam is more about WHAT a service is and the new exam is about HOW and WHEN to use the service or feature. I disagree. I felt that this exam had mostly HOW and WHEN questions. I used this course, A Cloud Guru, Certify You practice tests (from Udemy) and Whizlabs to prepare.
I didn't find Whizlabs particularly helpful... most of their questions were direct copies from A Cloud Guru and Certify You. Only A Cloud Guru and Linux Academy had actual learning courses and I recommend both.
Tips for preparing for the exam:
1. When doing practice tests, see if you can read the question and know the answers before looking at the choices.
2. When looking at the choices, see if you can reason in your head why it wouldn't be the incorrect answers. For Example if the question is "What database would you use if you wanted a SQL database that would be fully managed and wouldn't have to worry about doing any maintenance on it?"
(Note: no questions on the exam are this easy).
Reason... Lambda isn't a database; DynamoDB is a NoSQL database; RDS is managed, but not fully managed, you still need to do patching. However, Aurora is a fully managed Database and AWS performs any necessary patching. The answer is Aurora.
If you don't know what Lambda is go study it. Even if you get the right answer Aurora, but aren't sure why it wouldn't be RDS as well... look it up and study it.
If you can answer questions on the practice exams with this methodology, it greatly increase the bandwidth of your knowledge. So, its not only important to know what the answer is, but also why it isn't one of the other selections. REMEMBER the goal is not to come up with the right answer, but rather to master the concepts. This is key to passing the exam.
Aside from the practice tests and courses read the white papers and DON'T OVER LOOK reading the FAQ on core features such as Auto Scaling, ELD, EC2, RDS, Lambda, CloudWatch, Etc. I wish I had done more on that with my preparations.
In terms of questions that were most common on the test... I had a lot with ELB, Auto scaling... however, the tests are not all the same. Others have said they had 3-4 on Red Shift, but I didn't have any on Red Shift. The questions com from a pool of questions so there is no way of knowing which subjects will be on the exam... one person on a discussion board said that they had no questions on ELB... I had several. So prepare well for all areas.
Finally, but most importantly pray... The LORD is good!