When we started doing our tests in the lab and started thinking about what we thought we would be seeing, we had a very clear understanding that it would not all be blue-sky conversions and that we would identify problems - some more severe than others. We were also pretty aware, that there would be areas, where conversion was just not possible.
But - I am pretty sure I speak for the rest of the group - we were quite surprised to see which areas this concerned.
On area where absolutely nothing could be converted was ... lines. Not only line art, not only complex line drawings ... but simply - lines.
Lines are done in OOXML as either VML or DrawingML and in ODF it is done using a SVG-derivative. The puzzling thing is, that this area is apparently simply left out in either of the converters. We made some simple documents (line.docx 10,47 kb) and (line.odt 6,60 kb) [I have re-made these for this article]. When converting these files using CleverAge 1.0 on Microsoft Office 2003 and 2007, Novell OOXML Translator (on Windows and SLED) or IBM Lotus Notes 8 (on SLED), the lines are simply removed. They are not altered, they are not just hidden, they are not moved to a different location in the document ... they are just removed.
This is another example of the overall observation from our tests ... the quality of the converters are simply not good enough today. If you look at the XML in either of the files above, you will see, that even though they look different, they basically specify the same thing (start and end-point for the line drawn), so technically it should pose no problem to be able to do a better conversion.
It is often said, that the main problem with converting from ODF to OOXML (and vice versa) is incompatibilities between the formats. This example is by first glance suporting this argument, but if you dig a bit deeper into the technicality of it, is simply boils down to a problem with bad converters.
Conclusion: The world is seldom black/white ... even if people are trying to convince you so. More often, the world is grey and depressing as a rainy day.