He’s right that Tufte doesn’t provide detailed information on how to do better (not in this booklet that is ;-), but Tufte made me feel good because I always try to use existings books (as opposed to writing inferior stuff) for courses whenever possible, supplementing them with light courseware like PP slides and lots of examples.
I knew there was a problem with slides but couldn’t really put it in words, it’s all much clearer now.
I also try to use more drawings and less text, and as Tufte implicitely suggests, handing out a detailed drawing and showing small parts of it on slides while talking is very efficient and allows your audience to really focus on what you’re talking about, without imposing the next slide please polka on them.
For me the main message of the booklet is that audiences need high-resolution (or high-information maybe?) handouts to fully get the message. So maybe we shouldn’t burn the PowerPoint CD after all, but at least be aware of the bandwidth of any channel that we’re using to deliver our message.