A frequently pondered question is what type of keyboard key is the fastest to type on, and the question is slightly flawed. Speed is not really a function of the keytype, it's comfort-at-speed we are optimizing for with keytypes.
TLDR - For comfort everyone needs a key force profile that avoids slamming into a hard wall (at least not often). For me that's clicky blue low profile, or a good laptop scissor membrane. Worst is red-linear.
My crediblility? I am a 52 year old programmer, and I've been typing fast all my life. I can type 120-130wpm sustained on pretty much any full size layout, joined or fixed - as long as it's content from my brain (typing tests are..uh, weird). I type for hours on end.. I have been known to code for 8-10 hours a day, for 25 out of 30 days. I will do 36 hour all nighters. I started programmingn at age 10. I sold a software company when I was ~30, for which I wrote half the code. Typing is my life.
You want to geek out on the mechanics?
It starts by realizing typing is BALLISTIC. When typing very fast, the goal is to avoid "hitting" any solid wall. There are two ways to acheive this. Floaty typing is when your fingers learn the actuation point they can feel (blue,brown) and backoff before you hit bottom. Bouncy typing is when your fingers push into a soft bottom (o-ring, membrane, bumper) and rebound off it.
Here is how the differnt keytypes achieve this:
Blue Clicky keys are like setting off a mousetrap. You push the keycap past the click-threshold, and the pre-loaded click-spring "fires" the internal slider past the actuation point automatically. The goal is floaty typing and infrequently hitting the bottom.
Membrane Bubbles (with or without scissor) are a different way of achieving a snap/click. The rubber dome underneath is not linear, the force curve rises to a peak, then the dome buckles and there is a "snap release". This is why many will prefer laptop membrane dome keyboards to expensive red or brown mechanicals. For years I used the old IBM thinkpad membrane keyboards on laptops and desktops.
Brown Tactiles are giving you a bump to announce the actuation point coming up, but you have to push over it yourself. There is no force release or snap like Blue or Membranes. They are less expensive and quieter than blue. The goal here is float-typing like blue, and if you don't hit bottom often, it's working. If you do, try blue, a different brown, or an o-ring to soften the blow.
Anything with a spongy bottom (o-ring, membrane, laptop keyboards with flex or rubber bottoms) are more like punching a speedbag. You are absolutely hitting the key bottom out, but it's softer, so it's more of a bounce off the bottom. Some absolutely prefer this to clicky keyboards.
And then of course, you can combine Floaty and Bouncy. Throw some orings on a blue or brown switch, and float and bounce your way to typing bliss.
