I've been looking at ergonomic keyboards for a while and tripped across this one recently. I quite like the looks of it, so I decided to mock one up using a 3D printer.
It's printed in two parts, so could be used split, but that's obviously not how it was designed.
First impressions: it certainly keeps your wrists in line with your forearms (little/no ulnar deviation) and it's quite comfortable. For me, I could feel stretching in my fingers when typing the G and H keys (I touch type); this could be my posture, the key positioning on my mockup could be out, or I might just need to get used to it.
Since it's in two parts, I tried tenting it slightly which felt really good and even made reaching the G and H keys less of a stretch.
No, I am not going to make the STL or Fusion files available; please don't ask :-)