I use the 9x12 and wouldn't trade it for one larger or smaller. Doesn't take up too much space and is good with two monitors although I use a single high-defininition monitor now. Having a couple of input devices really helps with the falling-off-the-table issue. My pen is set to always move at a 1:1 and the mouse is set to always have proportional movement/speed. So, depending on what I'm doing, I grab the appropriate tool.