“Visual customizability is okay. There are themes and colors to
choose, the usual. KDE and GNOME both offer more visual
customizability, but I don’t really see this as a core function of
an operating system (what ARE core OS functions these days?), so no
complaints here.“Functional customizability seems low all over on Win 7. You
can’t really get the system to behave like you want. Instead, you
need to behave like the system wants. Contrast this with KDE’s
extensive configuration system where every little keyboard shortcut
and fine nuances of window behavior can be tweaked until your
eyeballs fall out. OS X is similarly weak in this area out of the
box, but add-ons to tweak things can be installed. Doesn’t count,
though, I’m looking at out of the box functionality here.”