I've tried the Unison but out of the box it's a PITA to setup compared to Robocopy.

Don't get me wrong - Unison looks to be a great tool, but is not as easy to use or read about as Robocopy. Not sure why the author doesn't place it on a more commercial site (even like SourceForge or simlar) and document it a bit better, then it might get more recognition and use.

But basically within 30 seconds of reading you can use Robocopy, which I was not able to do the same thing with Unison.