Liberté Linux 2010.1

The first release of Liberté (2010.0, this one is actually the second release) used GRUB Legacy, and correct installation was a nightmare from the maintenance point of view. You can see for yourself here:
https://liberte.svn.sourceforge.net/svnroot/liberte/tags/...

Liberté had to be installed on a separate partition, which had to be the second one (Windows sees only the first partition on removable disks). I don't think that there is a relatively easy way to accomplish such an installation from Windows.

Syslinux, on the other hand, allows the distribution to be a simple directory on FAT/FAT32-formatted disk, and provides installers for both Linux and Windows — the installer just modifies the boot sector to load ldlinux.sys, and possibly also modifies the MBR if the installation is to a partition.

I think that UNetbootin (which I understand is essentially a wrapper around ISOs) is an unnecessary layer that complicates things.

By the way, I think that for LiveCDs (as opposed to LiveUSBs), GRUB and Syslinux are equally simple to install and to use, but I only tried GRUB — LiveCD support was removed from Liberté Linux before the transition to Syslinux.