A personal benchmark is a set of tests built from your real work that measures how well an AI meets your standards. If you're an editor, a test might ask a model to give feedback on an article opening, then check whether its suggestions strengthen the headline and make the opening more concrete. Your corrections become checks for what the model needs to get right next time. Run the same tests on different models, and you can see which one does the best work for you, whoever makes it—and whether a new model is worth switching to.