When I was prototyping (pun, ha ha) custom keyboard arrangements, the flat Maltron arrangement was quite uncomfortable compared to the Kinesis curved bowls. Maltron uses Cherry blacks in their one-handed keyboards. I don't know if that executive keyboard uses blacks, too.
I never saw a t box keyboard before.
That Wolf King disk keyboard arrangement intrigues me, but I vomit each time I type on one, because of the rubber dome squishy feel. The Wolf King version with a full keyboard attached SEEMED to have an acceptable key feel, but I've never found a display where I could type on a WK disk and full at the same time for A/B comparison.
Kinesis with Cherry browns is my perfect keyboard. In part because there's plenty of room for modding.