M-Tab on w32 (and other window systems?)

["Lennart Borgman" <lennart.borgman.073@student.lu.se>]

The citation below is from nxml-mode.info. Is this something that should be
adopted generally in Emacs?

"The traditional GNU Emacs key combination for completion in a buffer
is `M-<TAB>'. However, many window systems and window managers use this
key combination themselves (typically for switching between windows)
and do not pass it to applications. It's hard to find key combinations
in GNU Emacs that are both easy to type and not taken by something
else.  `C-<RET>' (i.e.  pressing the Enter or Return key, while the
Ctrl key is held down) is available.  It won't be available on a
traditional terminal (because it is indistinguishable from Return), but
it will work with a window system.  Therefore we adopt the following
solution by default: use `C-<RET>' when there's a window system and
`M-<TAB>' when there's not.  In the following, I will assume that a
window system is being used and will therefore refer to `C-<RET>'."