Keyboard key switch mechanism is surprisingly important. Here's a simple story.
before (2005 〜 2012), i was using Microsoft Natural 4000 and Microsoft Natural. On social networks {g+, Google Reader, Twitter, Facebook}, you can press {j, k} keys to go down/up by post. It's nice, but i recall for some reason i just don't like using it.
now, i'm on Truly Ergonomic Keyboard, it has mechanical keys, and i find that i started to use {j, k} keys for post navigation.
the ease of pressing the keys made a difference.
I have used mechanical switch keyboards before. Earliest is 1991, IBM Model M keyboard that came with IBM PS/2. Used it for half a year. My second one is “Matias Tactile” amazon, around 2002. Really nice. I realized the quality in keys just by touch and look, without being familiar with the phrase “mechanical keyboard”. Only after 2008 i joined team keyboard freaks.