>ISTR once you get it going, a PowerPoint presentation is just forward (and sometimes back). A skilled presenter can and would get used to advancing the screen a second before the next slide is actually needed.
>
>It would also enable those cases where it is physically not possible to run a cable from the presenter's device to the projector.

I can send it to you if you want to try it. Here, it was a terrible disaster. I do not even know why this is being sold now.