I have used the various DokuWiki slideshow plugins, and while S5 is a safe bet (with some theme modifications), I personally think the
Reveal.js plugin is the best one so far. While you won't get point-by-point buildups (I believe this is not possible with the S5 plugin either), the good-looking themes and transitions alone are worth it.
As far as
Impress.js go, it definitely has something going for it in terms of cool factor, but most of its functions aren't integrated into its DokuWiki syntax, and so you're anyways left with a comparatively bland slideshow. You could enable html and just drop the slideshow code in there, but then content creation won't be so straight forward anymore. I hope for better integration someday!
The Reveal.js plugin is very simple to use; H1 sections become Title pages, H2 sections become normal slides, and H3 sections become "subslides" of a H2 parent (available via down arrow/key). In my experience, subslides are good for more in-depth information, but they can also be used for not-too-important information that you might want to skip (depending on available time, for instance), or for extra material like links, reference material etc. that you don't even need to show during class. Or a combination of all these.
Regarding Reveal's PDF printouts, you have to print them one by one, and they look just like your slides with some additional information (title, date/time, url and page number) added in each corner. Some css'ing will rid you of what you don't need. You might also want to set the plugin's control config option to "false" to hide the arrows on the printout.
So S5 will probably be better for your PDF needs out of the box, but you could also just make changes to your theme's print.css file and print the page normally. But this is beyond the scope of this humble presentation.
Hoping this helps!