I use Windows and many of my friends who encouraged me to start using Evernote use Mac. One of the 'Features' I loved about the Mac version was how the Notebooks displayed.
With Window I have my 'Notebooks' in left panel but it is very very very limiting on how many levels deep I can stack therefore i end up with a lot of Notebooks. With the Mac version 'Notebooks' is listed in left panel but when you click on it all your Notebooks open up on the viewing panel.
I am providing screen shoots of Windows and Mac.
I would LOVE it is the Windows version of managing Notebook