For the past two years I have been using KDE as my desktop on linux machines running Ubuntu 12.04 and Linux Mint 13 (both 64-bit). Recently, I ran into Qt conflicts when trying to run molecular modeling software from OpenEye. The problem appeared to arise from KDE. Therefore, I tried other DEs, including Cinnamon, MATE, and Xfce. I got the best results with Xfce, and after spending time tweaking, I now have an attractive desktop as well as a fast and efficient system. Because KDE currently provides better support for multiple monitors, I still have both KDE and Xfce installed. However, I see that the Xfce 4.12 developer PPA is offering some enhancements for multiple monitor support; if this works out, I am considering switching from KDE to Xfce, because this will enable me to run all of my linux applications without conflicts. Thanks, Xfce!