The best keyboard I ever had the pleasure to use was the IBM DisplayWriter beamspring keyboard. Why?
- Long travel, the longest I have known.
- That prevents your from bottoming out on the key, reduces fatigue.
- Strong tactile feedback. You knew you struck that key.
- Exceptional overtravel. Having pressed the key, it enforced your completing the motion sufficiently to know you've finished the stroke.
- Scalloped keytop ranks. Rarely seen in typewriters where it would have been most useful, lets you reach upper and lower ranks with less effort, less fatigue, fewer errors.
All this to create an electronic keyboard that emulated the Selectric keyboard, with its excellent ergonomics, unmatched to this day save for a very few exceptions, the Model M a standout. But the DisplayWriter was the best. And repairable. Just huge, key modules were almost 2" tall. Oh, and capacitive contacts, no switches. I replaced possibly 3 key modules over 8 years of servicing DisplayWriter and similar IBM word processing systems. Just the best feeling keyboard ever, for me.
And impractical today. Who wants a 2-3" thick keyboard?