Allow keyword tagging in reviews

Presentation styles are often a matter of taste, not numerical rating; for many audience members, "high-energy" and "motivational" would be just as repelling as they would be irresistible to others. That makes those qualitative descriptors at least as important as numbers - and being able to navigate by them would be potentially even more useful.

Instead of forcing users to dive into the individual comments for a speaker, it would be handy if they could see some combination of structured keywords - tagging a talk as "funny", "informative" or "practical", for instance - and free tagging. Those keywords would also arguably be less vulnerable to gaming than raw numbers.