Some people are more visual learners, so they appreciate a spoken presentation. But writing it down forces you to organize the material better.
I think a nice, scripted and tightly edited video presention is a wonderful way to present many topics. But that takes a lot of work and requires certain skills to pull off properly.
@lupyuen
I agree though, that an long unedited video of an in-person conference is really difficult to watch and forces the viewer to do their own editing by fastforwarding and skiping through that long video.