Writing takes more time than producing videos? Are these videos largely unedited? And if so, how do you measure the time lost in the inefficiency of interpreting the video?
I can imagine on some very complex projects videos being a difficult medium. But for me it's great: I just record the things I want to get done, bring up examples from other websites, use the mouse as a pointer to direct the viewers focus. I summarise what I want to be done at the end.
Usually I send over the video and checklist of things to do.