LaTeX vs Powerpoint for presentations

In a single analogy:

LaTeX+beamer:PowerPoint::LaTeX:Word

I use beamer every day for my classes (I teach math) and couldn't imagine using PowerPoint/Keynote the same way. But for conference talks or opening-day presentations which are not rich in mathematical notation I like Keynote.

I think that the answer mostly depends on what is going to appear in your presentation.

If you need a lot of math, please use beamer.

If you have Images and you need to make some order on the space you have on each slide, I think PPT is more powerful. The reason is that it often happens that your images on the slide are quite larger than you expected and you need to resize them. With PPt this process is straightforward, with beamer it's very demanding (compiling, checking, re-compiling....).

I've never used Keynotes, I'm sorry.

I'm using LaTeX-beamer-PDF because of its comprehensive and partly unique features:

1. Math: With LaTeX the best mathematical layout is available
2. Sketches: With the tikz package any technical sketch or diagram is possible
3. Graphs: With the pgfplots package font consistent, complex graphs with overlay effects are possible
4. Videos, Animations and 3D objects: With the media9 package even embedding of 3D objects, animations and youtube videos into PDFs is possible
5. Overlay effects: With beamer you can overlay even between formulas and tables
6. Hyper linking: With beamer you can link and connect anything, formulas, table of contents
7. Layout: Total control of any layout aspect (theoretically)
8. Self-contained: All information, all layout controls in one single text file and all media content embedded in one single output file
9. Standardised: With the PDF output format you are independent of proprietary viewer formats and software versions! (I started with beamer after I was forced to present my PowerPointless presentation with a different PowerPoint version: Some formatting changed and my animations didn't run!)
10. Typography: The default beamer layouts and font selections guide you in good presentation techniques (not too cramped, etc.)
11. Costs: Free of them!

But I'd also like to mention possible disadvantages of Latex-beamer, compared to WYSIWYG solutions, for example, Libre Office's Impress or PowerlessPoint ;-)

1. The learning curve is steeper, but excellent tutorials and user communities (TeXamples e.g.) are available
2. Command syntax is harder to memorise and type, but the LaTeX and beamer manuals and references are excellent and widely available.
3. Image positioning remains somewhat cumbersome :-/
4. A cold, sterile and a bit too perfect impression of your presentation might ensue
5. Often corporate presentation templates are not available for LaTeX (but it's worth to redo them in beamer ;-) )
6. Sharing with WYSIWYG content is difficult, the majority in business environment is using PowerPoint :-(
7. Expressing oneself in a mark-up language like LaTeX compared to WYSIWYG is brain dependent and might be more difficult for some humans. ;-)

By the way, I'm using now org-mode to write my beamer presentations (and anything else textual) to save myself some of the cumbersome aspects of the LaTeX language among other advantages.

By, by the way, lately I discovered Reveal, the html presentation framework. Which is also looking interesting when considering to publish the presentation on the web.