First, a little history.
On one hand you have the 'traditional' bump position, about half way down the key travel on the other you have zero pre-travel switches.
The basic, common examples of 'traditional' bump switches are Cherry browns. The switch is perfectly fine, although it is not the smoothest (it's scratchy), neither is it the most stable (it wobbles) nor is it the most tactile (the bump is too subtle).
Cherry made another switch, the Clear, which had a much stiffer bump. This stiffer bump was balanced with a stiffer spring which, by fortune or by design, created a most incredible switch feel. The stiffer bump provided a hard resistance before actuating*, but immediately after actuating there is considerable resistance which prevents bottoming out. Individually, if you're careful, you can tap on any switch (brown, red) without bottoming out, but this is much harder to achieve when you're typing with speed of thought. The force curve of cherry clears encourages this and is why it is so highly regarded in the community.
Unlike now, where the market is full of switches of all varieties, all competing with one another, giving you a range of options, there use to be far fewer options. Let's say for the sake of argument that the choice of tactile switches boiled down to Cherry Browns or Cherry Clears. OK?
OK, Clears improved on browns in many ways, but they weren't without issues: The spring weight (which contributes to this wonderful force curve) was very high, too high for many. The stem is MUCH tighter than regular Cherry stems, so much so that removing keycaps often resulted in pulling the switch apart. Then there is the infamous Cherry scratchiness (they are NOT smooth switches out of the box).
But that highly desirable, unique force curve led to early experimenting in the community. Lubing the clear stems improved the switch scratchiness issue, and swapping the spring for lighter varieties made typing for longer sessions less fatiguing. This modded switch became known as ergo-clears, and they are very nice to type on.
But the stem was still problematic: not only could you take your switch apart by removing your keycaps, you were also stretching the keycap to the point that it might not grip normal switches properly again.
Then came the Zealio.
To be continued...
* wether you realise it or not, the ability to play with the switch pre-travel, before actuating, is quite comforting and adds to the tactile pleasure of mechanical switches, compared to the mushy, inconsistent common rubber-dome counterpart.
