In classroom settings, slides are a poor local optimum. Personally I feel that professors rely on slides too heavily and would strongly them to use chalk. Writing in real-time forces you to teach at the pace of human thought.

This also allows students to take notes and actually absorb the material - otherwise, there is a tendency to pack too much into slides and you end up loosing half your audience. Although sometimes helpful for giving visual intuitions, more often than not, slides just get in the way.

When there really is no alternative to slides (e.g., for workshops and conference presentations), I find LaTeX/Beamer much easier to handle. It has good defaults and does not require fiddling with transitions and formatting and superficial but ultimately pointless settings.