Xubuntu tends to be one of the first recommended distros for computers with limited resources such as CPU power and ram. Xubuntu as the name implies used the xfce desktop environment. XFCE is promoted as being stable, light, and configurable.
In the educational environment I supported a cart of low end netbooks with 12.04 Version of Xubuntu. In general, my experience with the netbooks was sluggish at times and lack of responsiveness. By responsiveness I am talking about a "real time" user interaction.
The set up was the same as Lubuntu and Arch Bang, 500 MB of ram running on an ISO. Although initially they was a delay opening Firefox, on later attempts Xubuntu opened Firefox with 5 seconds.
I liked the Whisker Menu. It was fast and responsive and fit naturally into XFCE. I tried it in Cinnamon but did not like it as much on on Xubuntu. My only criticism is that the groups / applications seem to be reversed from what I am used to.
The big disappointment was the Ubuntu Software Center. The wait time was entirely unacceptable. I realize Software Centers generally are slow and bloated, but Ubuntu Software Center borders on pathetic. Maybe Ubuntu Software Center's poor performance was due to the Live DVD environment. Has anyone used it with good results?
While Xubuntu certainly plays second fiddle to Lubuntu, I am impressed with its development since the last LTS.