> I'm typing this on a ZSA Moonlander, which after the month or so of getting used to, I am never going back to a non-split, non-ortholinear keyboard again.

For me personally, the concave keywells of the Kinesis Advantage 2 are much more important than having a split. I guess because the fixed setup of the KA2 is just right for me. The concave wells mean that I do not have to stretch or move my hands for any of the keys. In Emacs, using "n" and "p" for next and previous requires no stretch at all using the KA2. My hand can stay completely relaxed while having one finger resting on n and one resting on p. The thumb clusters of the KA2 are also well suited to Emacs. I map Ctrl and Alt on both sides, so I can always choose an opposite-side thumb to press the modifier. I can also press both Ctrl and Alt simultaneously with my thumb, on either side. I would have given up on the default Emacs keybindings years ago if it were not for my KA2. I have one for work and one for home. It is by far the best keyboard I have ever used.

I'd argue the kinesis is a split board too - whilst technically not independent pieces the layout satisfies the criteria of a split board. In my humble opinion.

Is the kinesis sufficiently wide enough? I use my split board slightly wider than shoulder width. I'm also a big guy (as broad - 25inch yoke width)

I agree though, a concave keywell would be a big plus - in conjunction with ortholinear and split board.

> Is the kinesis sufficiently wide enough? I use my split board slightly wider than shoulder width.

It's definitely narrower than my shoulder width, but I don't mind the slight turn-in of my hands, my wrists are still straight. I can still rest my elbows on the chair arms and type.

Even if your wrists are straight, what are your shoulders and shoulder blades doing? How do they sit in relation to your spine? The kinetic chain is more than just hands and wrists

I recently bought a Kinesis Advantage 2. Could you be more specific about how you've mapped Ctl and Option? I mapped Delete and End in the left thumb cluster to Ctl and Option resp. What did you do?

I've mapped Ctrl to the big middle-lower thumb key on both sides; and Alt to the smaller middle-upper thumb key also on both sides. Space is right thumb rightmost big key, backspace is left thumb leftmost big key. Windows key and Delete are small keys; and do require a bit of a reach of the thumb. But I don't use them much (e.g. for delete, I'll do Ctrl+D). Enter I put in its usual place (i.e. not a thumb key). In Emacs I use Ctrl and Alt more than Enter, Space and Backspace. And I like to press them with opposite hands like shift, hence I have them on both sides. This helps avoid stretching.

When exported as a text file from the Advantage2, my mappings look like this:

  [=]>[`]
  [tab]>[\]
  [caps]>[tab]
  [up]>[down]
  [down]>[up]
  [`]>[=]
  [lalt]>[lwin]
  [ralt]>[delete]
  [\]>[']
  [lctrl]>[lalt]
  [delete]>[lctrl]
  [rctrl]>[lalt]
  [enter]>[rctrl]
  [']>[enter]