Every time you plug in a USB devic, an annoying notification appears on the screen, and even on a fairly large 1920x1080 monitor, this is still greatly annoying. Luckily, the notifications are usually rather useless, and so, can be safely disabled.
However, I would personally have preferred a small "x" type close button, instead there seem to be a "sticky" button, which I have no use for personally.
I am currently a KDE users. I have tried other desktops, such as Unity, Gnome and Xfce, but seem to have finally settled with KDE.
This is one thing that has annoyed me for a long time, however. It turns out there is an easy fix within the system settings.