I agree with K.Mandla's post above about Xubuntu becoming essentially regular Ubuntu with Xfce thrown on top. The devs just keep adding more and more GNOME components, always justifying it with "well the dependencies aren't too bad" or "well the dependencies are already in there" blah blah blah.
I tried Zenwalk and it didn't like my hardware as much as Xubuntu did, unfortunately
If you're after a XFCE-driven desktop, I had good luck with Wolvix on old hardware. It's what I would be running if Ubuntulite hadn't been resurrected.