Better tactile feedback and more reliable input means I don't have to constantly multitask half a task worth of attention onto making sure the input I think I'm doing went off as intended, which makes it easier to concentrate on the main task, which reduces the build up of fatigue, which reduces the rate at which the cost of mental effort increases throughout the day.
Which is not to mention things like the chance of getting hand cramps from the additional tension there caused by interacting with a less reliable keyboard, and by the tendency to use excess input force in attempt to get strokes through more consistently.
So if you are typing a lot, I would recommend getting an ergo before you start having issues.
For reference I could type about a paragraph in one go on a regular keyboard, now I can type an entire page before I start having pains/cramps.
What has always stayed with me was her guidance on posture and form. The 'piano style'* on which she insisted is almost completely contrary to modern ergonomic teachings, and yet I can say almost 40-years later; still works and is effective.
I readily admit that I'm probably lucky too in that I don't follow that guidance to the T, I do however follow the basic form of it. This anecdote simply agrees with your statement.
*: 'piano style' wrists higher then knuckles, finger-tips hovering/barely touching home-row, back straight
What? That seems to be exactly the current advice.
http://ergonomictrends.com/proper-ergonomic-typing-posture-a...
http://ergo.human.cornell.edu/ahtutorials/typingposture.html
(First two hits from a Google search.)
I tested using by high end gaming mechanical keyboard at work and my error rate went down a lot
Personally: I spend ALL DAY typing. Configurations, code, documentation, tutorials, arguments for doing things one way or another, user stories for work, chatting with my coworkers, running cli commands.
I see a huge difference in my productivity between myself and my peers partly due to my faster text input and editing skills.
Yeah. Yet, when you switch to a completely different (and maybe not very comfortable) keyboard layout and get slowed down to 50% of your usual speed and make a lot more typos, it just immediately shows how incredibly frustrating coding can get even if typing isn't the primary challenge in it.
Input should flow effortlessly and comfortably. That just makes it easier to focus on the more important stuff.
I've heard the refrain "you don't spend most of your time typing when programming" so many times it's almost become a trope. I personally spend enough time typing during a typical day (working or otherwise) that I really appreciate the benefits of a highly optimised keyboard setup, although of course YMMV. I don't think the argument holds water.