There was no link. A general search on Google will explain why looking at one's keyboard to find the letters slows down typing.
The point of
unmarked (or covered over) keys is that there is no benefit in looking away from the monitor to look down at the keys to "cheat." It takes time to learn to type with "DasKeyboard Ultimate" (or the like), but for those for whom speed is important, the effort is worth it in the long run. One looks at the type appear onscreen and not at the fingers or keys.
Back in the olden days: Steno pools were rooms filled with typists. Rarely would one see a typist looking at the keyboard or the paper in the typewriter. The eyes were fixed on the source document or book that was being typed onto paper.
i.e. Unmarked keyboard = the same concept for the computer age.
P.S. But getting back to the point of the OP who preferred the G5 keyboard . . . I wanted a keyboard that had a look and feel more like the electric IBM typewriters I grew up with. I went with DasKeyboard because it met those requirements and reminded of the G5 keyboard's behaviour. As a bonus, it provided a way to learn to type faster. (Note: Stickers or paint over the G5 keyboard markings would have achieved a similar goal, but DasKeyboard offered me the opportunity without having to mark or damage the original G5 keyboard.)
DISCLAIMER : I am not paid to endorse this product nor do I own stock in the company. Just my 2-bits worth.
