I saw a talk today that suffered from too much ‘pretty’ and not enough content. It reminded me of little kids playing dress-up. They’re wearing the fancy clothes, but they sleeves and pants are too long and end up looking silly. If you slap a bunch of fancy typesetting and animation on a presentation that doesn’t really say anything. Your audience will spot it. It’s better to have something that’s not perfectly polished visually as long as the content is solid. You need to have a story, entice your audience into following you through it, and then deliver it confidently.
Having a pretty slide deck can help make your presentation more memorable, but if all you have are pretty slides then your audience will still forget you by the next day.