Before you start playing with Alt-Ctrl-Shift-S (like I just did!) please note that it removes all your custom buttons both in the left and top buttons menu....

It's interesting that you want smaller buttons, I had the opposite opinion when I installed XD6. I think it comes from the resolution of your screen. I am working on a 24" 1980x1200 screen and I have plenty of room for bigger buttons.

JimR