well, it has been a while since I wrote that guide (it’s for a much older version of Ubuntu than the current), but I am running Hardy Heron LTS on my Samsung R55 this instance, and I can confirm that all those Fn keys that I use regularly work, which include:
- display brightness
- volume control (although you won’t have this fancy OSD as in Windows, instead it will simply affect the GNOME volume control)
- mute sound
- suspend
- enable / disable touchpad
- enable / disable WiFi
- enable / disable backlit
- enable / disable numlock

there are two keys of which I am not entirely sure what they are supposed to do: the one with the “silence” gesture (index finger on lips), and the one with the empty battery picture. So I cannot confirm if they work or not.

I am also not entirely sure about the VGA output switch, which you use in order to control the VGA output for e.g. using a beamer. I had situations where it would not work properly, but in others, it worked just fine. You’ll have to try out yourself.

All in all, surprisingly many keys work, however.

but I’d like to know more about function keys functionality (Fn keys).
does it work for volume level, mute, hibernate etc?
witch functionalities doen’t work?

thanks!