To be fair OOXML supports features that have been in Office for a really long time and ODF simply does not. That said, for moving data around, ODF is the forma

To be fair OOXML supports features that have been in Office for a really long time and ODF simply does not. That said, for moving data around, ODF is the format to use; use OOXML only when you need explicit Excel/Word/PPT compatibility.