I don't have much first-hand knowledge of that subject, but here is what I have ...

I don't have much first-hand knowledge of that subject, but here is what I have read.

docx:

   * Is horrifically complicated.
   * Is not likely to ever be completely implemented by any third party.
   * Does not accurately describe the behavior of MS Office.
   * Was rammed through the standards process in a way that demonstrated partisanship more than technical merit.

Whereas this offering by Apple does not seem to exhibit any of those properties.