I'm using ctrl pg up/down to move across tabs in my browser all day long. I can't see myself rotating a knob to do that. It's a very different movement and it's not discrete, too easy to move too far.

I didn't notice all the missing important keys.

~ del pgup pgdown ins home end

And cmd and opt have no place in a Windows or Linux machine. There should be alt and windows/super there. Seeing cmd and opt constantly remembers the owners that they are using a keyboard for Macs. Maybe they'll build one for Windows and Linux if they'll be successful at selling this one.

Now that's a constructive idea. I still like my Page up and down though but that's not a bad idea either.