In particular, Brad highlighted a taxonomy of entrepreneurs he's never seen before:
Diamond: Visionary dreamers leading disruptive ventures (Mark Zuckerberg, Sergey Brin / Larry Page, Ted Turner, George Lucas, Elon Musk)
Star: Charismatic individuals building personality brands (Oprah Winfrey, Martha Stewart, Richard Branson, Estee Lauder, Giorgio Armani, Jay-Z)
Transformer: Change makers reenergizing traditional industries (Howard Schultz, Ray Kroc. Ingvar Kamprad, Anita Roddick, Blake Mycoskie)
Rocketship: Analytical thinkers making strategic improvements (Jeff Bezos, Bill Gates, Fred Smith, Michael Dell, Mike Bloomberg)
I find these personality heuristics interesting and a great tool for self-reflection. The other heuristic comes to mind is what Malcolm Gladwell did with his Connector/Maven/Salesmen labels.