I used to run 3 displays, but am back down to 2, after giving one to a friend in need. They sit side by side.
I don't usually have to do much back and forth craning of my neck, because the console view on on display is generally only referenced when adding buses and effects, and of course while mixing. Most of the time, I am doing tracking and edits on my larger display, and as long as the levels are reasonable for track/bus volumes I don't have to look at the console view on the 2nd display much at all.
If you weren't aware of it, you can drag the screen order around on that Extend Display dialog box, so that if you want your primary display to be on the right and your 2nd to be on the left, dragging them around will then let Windows know how to display the mouse when you drag it off to the side. So, for me, my primary display is on the right, and I want to drag my mouse to the left off the edge and have it show up on the 2nd display, which is backwards of the default. So, to accomplish that, I dragged the 2nd display to the left of the primary display in that dialog box, and poof it just works like I want it to.
I LOVE having the 2 displays.
Bob Bone