Warren Buffett heaped praise on Amazon.com (ticker: AMZN) CEO Jeff Bezos and bashed Treasury bonds as an investment while Charlie Munger advocated a single-payer health-care system for the U.S in an appearance with Microsoft co-founder Bill Gates on CNBC this morning. The 86-year-old Buffett, fresh off a long performance at Berkshire Hathaway's (BRK.A) (BRK.B) annual meeting Saturday, said Bezos is the rare corporate leader who has succeeded in a big way in two businesses: online retailing and cloud computing. "I was impressed early with Jeff but I didn't think he could pull off what he did."