As gumby says, the Space Cadet keyboards, being Microswitch Hall effect-based, were a bit spongy due to the big plastic case, but the switches themselves were dreamy.
By the way, after 40 years of despairing over the loss of Hall effect switches (I nursed a Space Cadet Livermore Labs clone from a group buy for some years into the mid-80's), there are now two keyboards using this technology, and I'm loving the one that's actually available.
The CADR space cadet had a spongy feel, probably because of the large size and plastic case. A sad dependent of the Knight TV keyboards. With the 3600 series Symbolics replaced that with a solid keyboard (fewer keys though) that was more satisfying to type on.
Some of those keys like thumbs up/down etc were never really used anyway.
But the whole experience was still not as satisfying as the original Knight keyboards, I suspect because the Knight boards used the original, larger switches, while the Space Cadets used the smaller. Chyrosran22 on Youtube explains all this (https://www.youtube.com/watch?v=pcdN4Vzg6_g and https://www.youtube.com/watch?v=oDozftThFMw).
By the way, after 40 years of despairing over the loss of Hall effect switches (I nursed a Space Cadet Livermore Labs clone from a group buy for some years into the mid-80's), there are now two keyboards using this technology, and I'm loving the one that's actually available.
Steelseries Apex Pro is what's now shipping, and it's a dream. (https://www.amazon.com/SteelSeries-Apex-Mechanical-Gaming-Ke...)
The Input Club Keystone is still coming, slowly (https://kono.store/products/keystone-analog-mechanical-keybo...), but I'm also really looking forward to trying it.