"2. No more 'lock down'
With Windows or OS X, you get what you get and no more. Of course,
you can install third-party applications in Windows, but you'll
never have the flexibility you would find with a Linux desktop. And
if you don't like the desktop you are using in Linux, you can
choose a different one.
"Because Linux distributions are not locked down to any one
window manager or desktop, you should be able to find exactly what
you want. Whether you want a complex desktop, just the bare minimum
or something in between, Linux can make your desktop be and do
anything you want.
"Equally, you need not fear too much configuration or too many
options. You can start with the basic desktop and live with that
all your computing life, if you so choose. Eventually, however, you
are likely to discover how far you can bend the desktop with Linux.
Bend away -- it will not break."