I haven't also tried the S one. But my intuition is the following. The surface of the tablet is mapped to your screen in terms of input. The Intuos M is just a

I haven't also tried the S one. But my intuition is the following. The surface of the tablet is mapped to your screen in terms of input. The Intuos M is just a bit smaller than 13 inch laptop screens. So what you see on the screen is roughly the same size as what you draw with your hand. Additionally, while writing at normal pen/paper size, my hand moves comfortably from the left of the tablet to the right as I write across the whole screen. If I had to use a Intuos S, then I imagine, I would have to write a lot smaller with my hand, but then have it appear as bigger on the screen. But my hand would not move a lot, and making tiny characters would tire my hand out faster. I think my brain would get used to it, but it will still be a jump.