I hear that the basic ones are very easy, but the professional ones have a bit of heft to them. From a business standpoint, there's no reason for these to be too hard on developers--AWS is trying to push its agenda and needs workers ready with shovels to do so. The benefit could be to identify the most eager partners who can pass a basic competency check to reduce implementation risk, and of course, the training can tour you through the gamut of AWS offerings.