By Amy Or Of DOW JONES NEWSWIRES Greenlight Capital's David Einhorn vouched for Apple Inc. (APPL) in his speech at the Ira Sohn conference in New York on Wednesday, saying the company is a "great company with great balance sheet." He said some investors' concern that Apple can't maintain its hyper growth was based on the "misunderstanding" that Apple, like other hardware manufacturers, may suffer from a one-hit wonder. But the hedge-fund manager said Apple is a software company that can get consumers hooked onto its products through its various hardware products. The value investor said Apple's current value "isn't demanding," as "most cellphones aren't smartphones and tablets are still young and immature." On Apple's huge cash holdings, Einhorn said Apple doesn't need to give out dividends. Rather, he said the company should issued preferred shares, as it doesn't demand an immediate use of cash and poses no maturity or refinancing risk. In his over-100-page slide presentation, Einhorn commented on an eclectic range of stocks and topics, including his dislike of Martin Marietta Materials Inc. (MLM), saying the company "has a lot of problems"; and China, cautioning the nation's credit tightening may stifle economic growth. He also criticized United States Steel Corp. (X) for generating a loss despite its iron ore cost being just over a third of what its competitors had paid.