Like many sysadmins I learned to type on an IBM Model M keyboard. That was a mechanical switch keyboard and any time you made a key-press there was a click sound. It was also made to engineering standards unheard of today, and the very keyboard I learned to type on two and a half decades ago would probably still work today if it were still with us (it got lost in the great AT to PS2 interface switch).
That keyboard was a joy to use. Good key travel, nice feedback when typing.
However, it had a bad habit. It was noisy. A fact I didn't mind since the computer was in the basement and I didn't have to share that space with anyone.
Fast forward to the modern era of open-plan office space where even the paltry protection of our cubical walls is being taken away from us in favor of tables in clusters and such keyboards are downright anti-social. Pack 5 power-users into a small space with concrete floors, give each of them a mechanical switch keyboard and it'll sound like a horrible accident at a pachinko ball factory; only going on for 9 hours.
Like many sysadmins I've learned to type really fast. When I'm rattling out command-lines as fast as I can think, it can sound like repeating gun-fire (really: that analogy was drawn for me back at WWU during an intense trouble-shooting session at 4am).
As a kindness to my office mates, I stay away from mechanical switch keyboards and stick with the soft thud of a scissor-spring keyboard. Since I learned on a Model M, I hit those scissor-spring keys with about twice as much force as I need to so even they clatter a little bit. It isn't as nice as that old Model M, but it sure as hell is a lot easier to live next to me as a result.
Back at WWU when I shared an actual office with one other person I could possibly have gotten away with a mechanical-switch keyboard. Now that I share a table-cluster with two other people, and we're close enough together we can hear each other mutter darkly as we debug, that's no longer the case. Head-phones to drown out the typing sounds of your neighbors should not be required-issue for working in an office.
My current office keyboard is not the engineering marvel of that Model M. It's only 8 years old and most of the home-row key-caps have simply eroded off. What's more, there are very shiny spots on the spacebar where my thumbs have polished nice divots. Also, the U and the I keys are beginning to get erratic. It's probably time for a new one.
Happily, like that Model M, they still make the model I'm using.