For me, it's Kensington Slimblade¹ sunk into a desk cutout, since wrist extension (bending up/back) is an RSI problem for me.

¹ https://www.kensington.com/p/products/electronic-control-sol...

That looks pretty nice too although the angle of it concerns me a bit. I use a standing desk so it looks like it might require me to bend my wrists backwards a bit more than the Orbit. I might give it a try though.