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I know exactly what you feel. In some situations, having 90% compatibility is almost just as bad as having 0% compatibility. IMHO, one has to live with the fact that sometimes you just can't use the tools you prefer. If you try to make do with bad compatibility you end up hating the not-quite-compatible FOSS application, when it may be a great tool on its own if you remove the strict format compatibility requirement. It's a good thing to raise awareness about alternatives, but you have to keep your marks and then your job.
I most appreciate OO's compatibility with MS Office when importing documents, but AFAIK, completely seamless interaction between the two office suites is just not possible at the moment.