I agree with everything PK says and would add one more thing: JL does an amazing job of staying out of the way of the answers. Most interview style books allow way too much truncation of the answers by the ego driven interviewer, usually right when you can tell the answer was about to get interesting. Well done.
She's a superb interviewer. This isn't your 60 Minutes style of interviewer where she's the star and the subject is simply the vehicle to make her look smart, etc. Also, Paul Graham's forward is one of the best essays I've read in a long time. And, perhaps, the best opening paragraph. Damn, the man should be hired just to do that. The sprinter metaphor: genius.
How does he sleep at night? He writes ten or eleven blog posts a day, reads half a dozen papers, dozens of blogs, writes weekly newspaper columns, and runs a VC firm. And on top of that he still reads a ton of books. Amazing.