I use Unison, and I have 2.40.x in Fedora and on the CentOS box I sync with on the other side. And since Debian and Ubuntu also ship 2.40, that would work equally well.
Truthfully I didn't know there was a stable version 2.48. If I could get it on CentOS and Debian, I'd be happy to run it in Fedora as well.
I wonder why the distros have never upgraded to at least 2.45 if not 2.48.