RebeccaBlackOS Is a Class Act
RebeccaBlackOS offers an interesting window into where the Linux desktop might be headed. The developers behind the scenes working on Wayland seem to be making far better progress than the developers working on the Wayland fork Mir. Ubuntu designers have not yet been able to get Mir working with any desktop environment. The last few Ubuntu releases have bypassed the planned Mir debute.
RBOS gives you enough stability to play around with a variety of user interfaces. It's encouraging that KDE and Gnome 3 shells work so well already on Wayland. The Enlightenment desktop is one of the newest innovations available on several Linux distros, so it should continue to attract interest running so well on Wayland.