I prefer a combination of videos and books. It doesn't seem realistic with how content is packaged and delivered that one or the other entirely can work on their own.

I'm not sure where the idea of powerpoints came from. Well written books generally read like videos. Books have the added benefit that it's easier to jump around and drill down right to what you are looking for, something that's generally harder to hop around on the timeline of a video.

Still, Videos are excellent to watch for many things.

Updating videos though is tough, and it can cause videos to not be as up to date and indepth.