On a regular basis I get to watch demonstrations of various types of software. In almost all of them I prefer to see a recording of the demo which has had dead space or wasted time edited out. I would guess that more than half of live demos that I’ve seen have had one or more issues causing the demo to fail in general or in part as well as wasting time watching finger boning attempts to fix something on the fly or retry it. A recorded demo can also be replayed to follow the details or passed along. In my experience I never recommend a live demo unless you have a need to demonstrate that something works. For recording I also prefer to add a voice track and potentially text boxes here and there to explain what the intent is. This ends up with a professional result that you can re-use.