How Do You Like Your Screencasts?

Over on the Software Carpentry blog, I've posted links to three trial screencasts. We'd be grateful for your comments: do you like the format? Is the video quality good enough? Are the transcript and/or notes useful? Other than adding exercises (which we're going to try tomorrow and Wednesday), what could we do to make them better? And while we're on the subject, what are you favorite technical/training videos? Do you like the PowerPoint slides with inset talking heads of Google Tech Talks? Or do you prefer screen recordings with voiceover, like this? How about Common Craft's mix of cartoons and stop-motion film?