The best part is that he does very little editing, so you see him screw up and make modifications on the fly - nearly all other cooking shows/videos don't show that and so you feel like everyone can cook perfectly. Kenji will forget to add things, or burn things, or do things out of order, but he keeps rolling with it. To add to the videos, he has the best articles on seriouseats.com that explain how and why everything is done in the recipe.
indeed... that and not following the recipe by the book and substituting or paring down the recipes for a more accurate representation of what cooks do at home. also suggests what you could add or omit all the time.