Interesting... 6 years ago or so I tried the Microsoft Natural Ergonomic Keyboard 4000 (one their split models) at work and after some struggle abandoned it for a more traditional mechanical keyboard. Today I pulled it out of the drawer it was sitting in and gave it a go just because I was bored. Weirdly, I find it a lot more comfortable than I remember and the layout doesn't give me as much of a headache. I don't like how the key press feels, but that's kind of minor.

Maybe I should look into ergonomic keyboards again