I took the exam at re:Invent 2017 and passed thanks to Whizlabs! I purchased the acloudguru course and went through it and then, a few days before the exam, I purchased the WhizLabs course. I would say that they are each fantastic courses but for different things. WhizLabs is definitely what you want for passing the test. Many of the questions are exactly as they are on the exam. Acloudguru is great if you're wanting a deeper understanding of the actual AWS resources. Thanks WhizLabs!