Do you think your past study or continued study of outdated material will prepare you for the current/new PMP exam using the PMBOK Guide, 5th edition? As I finish up our 5th edition course materials, the unmistakably clear answer is no! There are simply too many changes. If you rely on 4th edition materials, in my opinion, you will absolutely fail.
Consider the changes, it is not just the reorganizing of the knowledge areas into 10 from 9, or 47 processes from 42, or 77 inputs and outputs from 80, or 120 tools and techniques instead of 129. All of these changes are rather deceptive because they involve getting rid of some items, merging others, creating new ones, and renaming quite a few. It is in the details where there are even more changes, many more. Some are easy to spot, like rough order of magnitude, which is now -25/+75%. Others, though, are not so easy to spot and there is no simple list of before and after at the detail level.