Hi all, probably this is the wrong place for this comment but since I am overloaded with work it should be better here than nowhere. :-)
I am quite pleased with calligra import of docx documents, sometimes my students send me docx documents with math formulas (or related) and I have been able to read them with calligra suite but not with libreoffice.
Note that this is only for reading and not writing or editing or whatever.
I should also say that I have written tips to explain them that pdf is a better format for file transfer FWIW.
Regards,