Open XML versus ODF

I have been reading several articles and blog posts the last while on the approvel process for Open XML in various countries. These include Open XML – US V1 Committee Vote and IBM Motivations, Microsoft guns Open XML onto ISO fast track, and Open XML Suffers a Setback on the Road to ISO Ratification . Setting aside the name-calling, accusations, insinuations and other vitriol which seems to pervade all discussion involving Microsoft and the open source world, I would like to better understand what the technical justification of ODF over Open XML might be (or vice versa). While I would not claim to be a technical expert in either format (though I know Open XML much better than ODF), the main arguments I have seen in favour of ODF are:

1. It got here first
2. It is not from Microsoft

I do not see either of these as useful arguments. Can anyone out there point me to real, meaningful, technical reasons why one is better than the other?