I'm mostly typing on Corne keyboards now; a split kit keyboard with 42 keys, so still considered 40%, but fewer keys than most other 40% boards. (so you have to learn to cope with not having dedicated arrow keys, for example) I can't imagine ever going back to a non-split keyboard; for me, it's a much better typing position to have my hands shoulder-width apart rather than squeezed together. I think that's more impor…
In fact I'm even thinking of building one with the outer columns chopped off if I can get a bit more used to chording.
It didn't at all take me long to get used to the 40%, the split boards, or the column stagger after using a 60% for years and I was quickly back up to ~100wpm in about a week. This was my first time with the three. Most of all, I'm never going back to a non split if I have a choice.