One thing about the original space cadet keyboard was that it was a crappy keyboard. It was made of nice cherry switches but the case was plastic and flexed (very) slightly. This need not have been a killer but the PCB was very long (look at all those keys!)* and lacked an appropriate rib to keep it stiff. So it would flex a little.

Now those keycaps were pretty big back in those days (no apple ultra minimal styling) so the displacement wasn't enough to mess up touch typing. But regardless, it was enough to make the keyboard feel slightly spongy, which was a shame as the key mechanism was really good.

Also the keyboard was too wide, (you had to take your hands off the keyboard to press some keys, like KTV (really an excellent keyboard BTW) holdovers such as ⊕ or new ones like . So in practice they weren't used so much.

This keyboard was only used on the CADR; later Symbolics and LMI keyboards still had a lot of keys, but were comparatively stripped down and more stable mechanical engineering.

* even bigger than the weird keyboards that have a pointless numeric keypad next to them that you still see sometimes these days.