My experience has consistently been exactly the opposite for 4 years now. I enjoy the beauty, simplicity, elegance, and ease of use of my favorite 'buntu derivatives without any loss of speed compared to my favorite Debian (direct) derivatives - including Debian itself.Ease and convenience comes at a price: Speed and efficiency are what is sacrificed in order to gain simplicity, beauty, and ease of use.
Therefore:
Debian + (Xfce/LXDE/KDE/whatever) is twelve zillion percent faster than X/L/K/whatever-ubuntu, and six zillion percent faster than minimal Ubuntu + Xfce/LXDE/KDE/whatever.
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