>looking cross-sectionally at the keyboard space while researching my purchase, I found that the opposite was mostly true in terms of what attracted the most attention. Strange.

It is not that strange - people who aim for ergonomic builds are a small community of an already small (if increasing) community. Most people do not want something like a new keyboard to mess too much with their motor memory.

That fits for me. I got two mechanical keyboards at the same time. One mirrors the Microsoft Ergo: cloud nine. The other is unique in the layout: ergodox ez. On this, my typing speed dropped to a third of normal. With the cloud nine, i typed at full speed minute one. The twice as expensive ergodox ez sits in my closet.

In my experience it doesn't take very long on a new keyboard set or even a new layout entirely before one gets fairly up to speed. When I built my Lets Split v2 ortholinear, I put dvorak on it and getting up to speed was surprisingly fast.

The ergonomic reasons behind the lets split/ergodox make them quite worthwhile. I love my HHKB2 but a split keyboard in general feels much better for my posture.