And things turn really "fun" when you begin using modifiers which aren't supported by the USB keyboards specs, like the Hyper key. I've got my Linux / X configured to use Super and Hyper keys but things quickly turn weird. For example the Hyper key works totally fine from Emacs in GUI mode (and, over the years, I assigned a huge number of shortcuts to the Hyper key), since years and years, but I have never spent the time to make it work in the terminal. It's doable but requires some arcane magic. I'm not even talking about having the Hyper key working from a tty (like if I boot in non graphical mode) but simply having it work from, say, an xterm under X. Oh the fun.

So until I fix that no "emacs -nw" (emacs in terminal mode) for me as I rely way too much on my Hyper key.