Workflow for round-trip with Sibelius

Hi folks! I'm considering getting this software. Does anyone use it for a workflow where you edit with Sibelius on the Mac as well?

In particular, does it have:
  • Dropbox integration (load-edit-save, not just import/export)
  • The ability to use MusicXML as a native format, rather than having to import/export each time? (So I can just open a MusicXML file and make changes, which get saved back into the same file.)
If not, is anyone using Symphony Pro in conjunction with a desktop score editor, and if so, what is your workflow?