Compatibility is a tricky business. If you shift a Word document to a device on which it was not created, what happens if that device doesn't support the font(s) used in the original? Sure, it opens, but due to the font substitutions, the formatting will be just as wrecked as if it was exported from another word processor. To really be on the safe side, in addition to everyone using the same software, the formatting choices have to be downright primitive to survive the sharing process.
In terms of sharing material, the best way by far is PDF, assuming collaboration isn't the sharing purpose. If the document will be a collaboration then one of the collaborators should be responsible for final production (preferably someone who understands document formatting). If you don't have that, then all the compatibility in the world won't produce a respectable document. My own experience with this is you have to strip out the grotesque formatting you get from your collaborators because they are using their high-powered word processors with all the finesse of a chainsaw.
Anyway, that's my lecture on word processing. Compatibility and power aren't nearly as useful or as important as widely advertised. Those two facts have given me the permission to use what I prefer.