The problem is though, 40 inch has a width of ~ 34 inch (?) vs 3 x 24 inch having a width of ~ 60 inches.
You take a big hit horizontally which is probably what most important axis when it comes to driving.
That is true, and pretty accurate - you lose the side inches. Still, I don't mind the swap. The bezel was driving me nuts, and I do need the height for work.
Also, I don't think I mind the loss that much. Most of it was unseen, anyway. They say it's all peripheral vision, but I'm not completely sure if it matters too much at all.
What I'd prefer though is a bit of curve in the monitor, and maybe an even narrower aspect ratio with a couple of inches extra in size.
So my next one is a 42" curved 21:9 monitor.
Although this one I could get into portrait mode with a good stand, and playing flipper on it could become a real treat...