Apple - Enabling remote login without password authentication
Allow me to answer myself as I found a resolution.
If PasswordAuthentication no
doesn't work on its own (and I read in some situations it may) make sure to uncomment and set to "no" this:
UsePAM no
Kudos for this resolution go to Mac OS X Hints - http://hints.macworld.com/article.php?story=20050815135941513&lsrc=osxh.