I'm uncertain of the value of the unconventional spacing, compared to, for example, spending the time to make a fully contoured key bowl à la Maltron.
A few thoughts about key wells like those found on the Maltron and Kinesis Advantage:I had the opportunity to try an Advantage, in fact I own the old Kinesis Contoured keyboard which Sordna sent around the world for people to try a few years ago. While I liked the thumb positioning better than the ErgoDox, I didn't care much for the bowls. My hands felt a bit claustrophobic and I unexpectedly found the finger movement less desirable than the ErgoDox's. I have pretty bad finger dexterity and found the varied vector paths awkward. This is not a criticism at all about the bowl shape in general, only an issue I experienced because of my limitations. Interestingly enough, the curves reduce the realized vertical spacing at the cap tops to a distance pretty close to my keyboard's spacing.
To further elaborate on this, I prefer a motion that hammers down on keys that are set in a parallel path rather than a motion that more resembles a poking or stabbing effort, particularly apparent on the upper rows. Again this is due to my fine motor limitations rather than a design flaw in a bowl design targeting the general public.
The same principle holds true for me with the thumb key action. I've seen designs that rely more on the gripping or curling of the distal parts of the thumb rather than a lateral movement hinged almost exclusively in the thumbs proximal region. Again, my superior large motor control is both quicker and more accurate than the former.
Because of the above, for those desiring a sculpted or curved profile, I think it makes more sense to accomplish it with the caps rather than at the plates. I made minor height deviations between rows to provide clearance but in some ways find it less necessary with 5 or less rows, particularly with reduced travel switches. The varied height also not only looks a bit erratic on a staggered column arrangement but it also can cause operational problems when traversing fingers between columns, e.g., moving finger almost laterally from a low #3 row cap to a higher #4 cap would require a finger lift to avoid hitting the side of the higher cap.
And while I'm on the whys of design, let's talk trackballs.On an earlier keyboard I made with an ErgoDox, I heard criticism about my incorporating a trackball. I think one comment was something like, "What is this, the 80's.". I had several reasons and I'd like to share them here.
First is footprint. A mouse, though small, requires a fair amount of space to operate. This is not a major problem on most desks but can be on a tray. I've found several advantages in using a tray, from being able to control height and negative slope to quick adjustability and the ability to get the keyboard out of the way when unneeded. A trackball shines when used on a tray.
Second is proximity to the keyboard. My center located trackball is 3 1/4" from home position with either hand on the AlumaPlop and slightly less on P6, which is very convenient. The center positioning also allows ambidextrous use.
Third is that I simply like the operations of the Slimblade.
And finally it's tactility is better for me than a trackpad. Because of the loss of a certain amount of sensitivity in my hands, I find that running my fingers over a flat pad just doesn't offer enough feedback. To further complicate things, my work leaves my hands sometimes so heavily calloused that the capacitive sensing doesn't register my hands reliably. I have the same problem with fingerprint recognition devices.
I guess I'm just providing more evidence that, as Zekromtor noted, "It's a keyboard designed by kurplop for kurplop".
(paraphrased)