Last year I met a writer who casually referenced "the AI-generated piece in the New York Times last week." I hadn't heard of it so asked for more info. She told me that she started reading it and immediately recognized the AI voice. "Of course that's chat. My bestie." She complained how she missed 4o but she was getting used 5, even if it was more difficult to talk to. And how she would recognize that voice anywhere. I was a little incredulous but Pangram agreed with her. Today in retrospect I think a lot more people can tell. But I was amazed at the time. She clearly had a highly attuned internal AI sensor from all of her time talking with "Chat."