I also thought the same, you would not recognize it most of the time (even while transferring). But I'm german and I use sometimes Umlauts in filenames/directories. They did not showed up in my Samba share so I got aware of this issue. I think this issue is too hidden.
If you want to read about this topic:
rsync: http://askubuntu.com/questions/533690/rsync-with-special-cha...
sshfs: https://github.com/osxfuse/sshfs/issues/14