This is just a splash for the Novices.. It covers the foundational - assertions of the mechanical keyboard hobby.
There is much more to explore, if you're after the details, BUT, this should get you started on the important basics.
0 - WHAT IS a mechanical keyboard?
--- ALL keyboards are mechanical, ALL of them.The difference comes down to their MECHANISM for key-activation along with the advantages and Disadvantages of said mechanisms.
On this website (Geekhack) and many others, people lump rubber sheet keyboards (the big-box store computers) as non-mechanical or rubber-dome keyboards.
Only the Cherry MX / IBM Buckling / Japan Topre / Japan Alps variety are considered colloquially as (Mechanical)
<not an exhaustive list, there are others, but these are the ones you can buy readily>
Overall it's important to keep in mind that fundamentally, all keyboards are mechanical..
1 - Why is Rubber-Dome considered bad? --- Big box computer keyboards cause Cramping because it teaches the user bad technique.- From big-box-computers, the typical Rubber Dome key activates when you press the key -all-the-way-down-.
Over time, the copper-contact-sheet beneath the key becomes worn out. The only way to reliably activate keys on a worn-out copper sheet is to PRESS-HARDER.
Most people who grew up with this type of keyboard and actively use them will develop cramping in their wrist or fingers due to "Unconsciously" utilizing excessive force to ENSURE activation...
Using significant down-force isn't the worst part about this, it's the HOLDING of the key at high force that ultimate does the damage to one's hands.
The fact that one needs high-force to ensure activation + the fact that the key only activates @ 100% of key travel (all the way down) causes people to Strike and HOLD..
The HOLDING is as if you're lifting weights with your fingers + wrists..
It's not a problem to do this for a short period of time, but add it up over hours and hours and hours.. You can easily see this turning into an ergonomic catastrophe.
One must understand that this HABIT of using excessive force is not learned overnight, it comes from a lengthy exposure to less-reliable keys..
2 - How are Mechanical keyboards any better?
--- They are more reliable and train you to type-properly. Mechanical keyboards activate @ 2 millimeters of travel,
regardless of how hard you've pressed the keys.. The reliability of key input does NOT change with Applied-Force..
This instills in the USER, the unconscious choice to Reduce force to only what's necessary. It will NOT cause the user to ever Hold-down a key, because holding down the key is of no use.. the key will activate past the 2mm point, the bottom of the keystroke is not directly related to input..
--- If you grew up on the traditional rubber dome keyboards, children of late 80s-90s. Then it is likely that you have learned the "tiresome" habit of Strike-n-Hold..
The only way to correct it is to consciously reduce not-only the applied force, but to RELEASE the key after you've hit the bottom of the key.
For a detailed explanation as to WHY you need to hit the bottom.. You may find such pertinent information in my 135 words per minute SPEED GUIDE.. linked below
https://geekhack.org/index.php?topic=67941.0 --- Learning to Key-Release, is the most grand advantage to mechanical keyboards. Knowing that they are not dependent upon high force / holding, you can more easily transition into the Ideal typing-release-technique.
3 - If Topre = Rubber-Dome, how is Topre better? --- Tell me about TOPRE:Topre IS a rubber dome keyboard.. It FEELS exactly like your familiar keyboard.. some even call it "homely (british)"..
The familiarity in "feel" is the foundation of its success..
However, Topre has retains the 2mm travel advantage of mechanical keyboards..
Despite the fact that Topre feels -good- to most people.. It is often the case that because Topre feels exactly like the cheaper-Rubber-sheet keyboards, it causes users to continue their bad strike-n-hold technique of typing..
-Strike -n- Hold technique is discussed in the above sections.
4 - Cherry MX, is cherry better or worse than Topre? --- Cherry Mx's primary difference from Topre is that it feels very different and more linear.. -less bump feel-This novelty in sensation is what triggers many users who are already adapted to strike-n-hold to relinquish the bad technique and adjust to proper strike-release..
I must note that it is NOT impossible to learn proper strike-release on a Topre..
-- but it's just often harder because
--- 1, the user might not be aware of the fact that he's been doing himself harm,
--- 2, the user might not know about proper technique..
- Essentially the Linear-type switches has Proper technique Built into its sensation system..
Whereas if you started with improper technique on big-box keyboards, Topre by design will not tell you what you've been doing wrong.. <this does not prevent you from correcting, it's just not obvious while using Topre>