I just like to tell you what still is a Problem in Ubuntu 14.04 and should be solved for a nice experience of this distribution. Unfortunately I do not have any hints to tell you, because I am just a user and know not much about programming. Anyway, I hope it helps.

1) Intel open source Graphics issues (proprietary)

-when attaching HDMI-cable the screen switches to the external monitor and it's fine, but there is no switching back unless restart with HDMI deattached

-black screen appears for like 2 seconds as if I would change screen in the settings; frequency increases with intensity of driver use (i.e. videos or video games)

2) hotkeys (commonly recognised)

-there is no possibility to adjust brightness with the hotkeys (Fn+F5 and Fn+F6)

3) touchscreen (commonly recognised)

-the touchscreen is behaving like a mouse

-configuring gestures for the multi touch screen seems to always end in disabling touch pad gestures

4) panel symbols

-battery symbol has got a low accuracy while it determines accurately the energy left; only 5 steps of energy are shown by the symbol

Thank you all for participating in the solution of these problems! I will stay tuned and edit this list if something has been solved.