I know plenty of ENTPs. They're abound in my line of work and career choice, my brother-in-law is definitely one, and I'm pretty sure my dad is, too.
It's awesome that they're so laid back and tolerant about everyday matters, yet they're very gung-ho about their various ideas. If they get past the tendency to be late and unprepared when it's necessary to be on time and well-suited, especially when it affects other people, they'll do well in life.
The archetypical crazy ENTP physicists working on our projects end up staying up all night to work out insane equations and models to present at a meeting the next day.. love it. Sometimes, they end up spinning their wheels because they're so passionate and going perhaps in a slightly different direction than our project is headed, but they don't usually end up discouraged because they love doing it, and they find a quick way to tailor their work to something more applicable anyway.
Some of them, however, don't seem to be able to step into another person's shoes at all. An immature Fe can step out in a bad way in fights, telling others what they should and should not be feeling in some given situation. This combined with a tendency to want to "fix" problems can be disastrous, because it will lead to a frustration in their inability to adequately resolve people-based problems.
