Know this won't be for everyone, but for those who've discovered PeachOSI and would like to add the more traditional MATE 1.8 desktop, either as an option to or a replacement for P_OSI's XFCE desktop, here's how to do it. Open a terminal window and run the following commands:
sudo add-apt-repository "deb http://repo.mate-desktop.org/archive/1.8/ubuntu
$(lsb_release -cs) main"
sudo apt-get update
sudo apt-get install mate-core mate-desktop-environment mate-notification-daemon
Once everything's done restart your machine. At the login screen, click the icon and select MATE as your desktop environment.