I've been using PDF for presentations for a couple years now. It's a safe option when you don't know if the presentation computer has the same version of powerpoint. Some features of newer powerpoint versions are not compatible with older versions. This is not really an issue for different Adobe Reader versions.

I also like this method of creating a presentation because it forces one to keep it simple. Whereas elaborate presentation slides take away from the point(s) the speaker is trying to make.

This is a handy way to make presentations - thanks for sharing!