I got both the older PiTop and the PiTop[3], and of course, the [3] was lacking, in that it only works with the Raspberry Pi 3, and has ribbon cables that don’t lend itself to upgrades, like the Raspi-4.
The older PiTop, the one with the track-pad on the right hand side and smaller keyboard, actually works a lot better, and strangely enough, seems closer to the CEED desktop in construction. I used the older PiTop to make an “infinite laptop”, which can be upgraded as long as the Raspberry Pi Foundation maintains the same form factor for the Raspberry Pi 5, 6, and so on (if there is going to be a 5 or a 6, that is).
I have more detailed documentation of my project here:
Infinite Laptop With Raspberry Pi 4