First: some people will always type faster than others, no matter how much others practice.
Second: a quality mechanical keyboard will allow you to type faster because you will type confidently thanks to its precise feedback. Such precise feedback lasts throughout the life of a mechanical keyboard, whilst -- as you have pointed out -- rubber dome keyboards are good only while they are new.
Third: typing fast is also a matter of economy of motion. That's the reason your friend can type so fast on a keyboard with a short key travel. So, a keyboard like his could be a good choice, if you are after speed. However, the consensus is that bottoming out is bad for the health of your fingers, and on keyboards with a short key travel you can't avoid bottoming out. If you type a lot, then that would matter and you may consider a healthier alternative.
Fourth: if you don't employ a formal typing technique, then finding a mechanical switch that works for your typing technique can be an expensive process. An expense that you may want to skip by grabbing a keyboard like your friend's, that you know it will work.
I'd like to mention that at higher speeds from large amounts of practice, say 120+, improvement is nonexistent unless one is able to frequently not bottom out. That's really the only typing advantage that mechanicals offer, the ability to not bottom out and register keys. I'm maybe a few wpm faster on my MX Blue board than HP rubber dome, but I also type on my Blue at night when I'm rather sleepy. I agree with the tactile feedback bit, it's very difficult for me to type accurately on mushy boards.
As far as the third point, though, short key travel does not equate to typing speed. I can relate this because almost all very fast typists use mechanicals without bottoming out much, while using a rubber dome leads to overuse in force, likely because of the variances in force required to depress each dome.
Can you explain how this user improved from a 120wpm average to her current overall average of 144wpm, calculated over the course of 12602 races on Typeracer, while using an non-mechanical keyboard
where she must bottom out each and every keystroke?So, I tend to agree with spremino's statement that: "typing fast is also a matter of economy of motion. That's the reason your friend can type so fast on a keyboard with a short key travel", as in the case of her keyboard, distance to actuation = full key travel (3.2mm). A person typing on a scissor switch is basically equivalent to someone not bottoming out as you say on a mechanical keyboard 'every' time, i.e. 100% not bottoming out.
Therefore, short key travel
does equate to typing speed.
scissor: short key travel == distance to actuation (2mm)
rubber dome: long key travel == distance to actuation (3.5-4.0mm)
mechanical: short key travel == distance to actuation (2mm)
**I assume your standard of 120+wpm refers to 10fastfingers? In this case, Fyda's average on 10fastfingers would be way higher than 144.
Highest wpm are recorded on typeracer because sometimes there are very short, easy texts.
But overall averages are way lower on typeracer, due to the addition of punctuation and capitalisation.
Let's compare 10fastfingers with typeracer:
ChimChim
10fastfingers:
average wpm 150
highest wpm 164
Typeracer (chimchimchim) - ranked 217:
average wpm 116.8
highest wpm 177
sean wrona (arenasnow)
ten fast fingers
average wpm 194
highest wpm 211
typeracer (arenasnow2) - ranked 1st:
average wpm 176.5
highest wpm 256