Ask HN: Exit Interviews, are you truthful?

Using a throwaway account since most of my company is on here. I'm leaving a large tech firm in the midwest and am thinking about what to say during my exit interview with HR.

What do you say in an exit interview? A great read on exit interviews is here (http://www.forbes.com/sites/jacquelynsmith/2012/07/31/you-quit-your-job-now-they-demand-an-exit-interview-what-do-you-say/) which has two schools of thought:

Be completely honest with their employers—dishing out constructive criticism, berating or praising colleagues, airing grievances, or applauding the corporation for its do-gooding ways.

If you don’t have anything nice to say, lie.

When you leave a company, what approach do you take?