Microsoft has taken a swing at the open source format, saying it's too slow:
The OpenDocument Format (ODF) has come under attack from Microsoft, which claims its Office Open XML format has significantly better performance.
"The use of OpenDocument documents is slower to the point of not really being satisfactory," Alan Yates, the general manager of Microsoft’s information worker strategy, told ZDNet UK on Wednesday. "The Open XML format is designed for performance. XML is fundamentally slower than binary formats so we have made sure that customers won't notice a big difference in performance."