Kaggle competitor here (3 times in the money) - ask me (almost) anything
Summary of answers: Paweł Jankiewicz
Source: https://class.coursera.org/datasci-001/forum/thread?thread_id=2770
Kaggle Chief Scientist here - Ask me anything too!
Summary of answers: Jeremy P Howard
Source: https://class.coursera.org/datasci-001/forum/thread?thread_id=3920