Why would one design a slider device where the bulk is in the display half, and not in the keyboard half?
I find it much more egonomically sound if I hold the fat and heavy part in my hands while only a slim and light display part slides out.

I believe, if feasible, the center of mass should never be above the upper edge of the lower half, otherwise I have to counteract the tilting momentum by constantly holding down the keyboard with my thumbs.