Neumann simulate their drivers and speakers and then measure them when the prototypes are finished. Listening is not part of the decision process. The main thing is rigorous simulation, testing and measurement. Their business and resources are of course very different since they mass produce a highly competitive and tight product list.
Jones works as a consultant or something like it. He designs drivers and the rest, and the way he makes compromises between significant defects is through the listening assessment. I would imagine at TAD the development and manufacturing allows more budget per speaker to introduce driver and other changes to improve the performance than elsewhere, so the results are better. But those are extremely expensive speakers relative to ELACs. The economics of these companies are strange in that sense. I think the only reason they survive is because technical assessment is not part of the mindset of the average customer. Reputation rules and allows the market to be inefficient. How good are the drivers Jones makes relative to offerings by Tymphany or Scanspeak? I would imagine they are competitive but need to be fairly cheap to make to justify customization, which means compromises need to be made.
Neumann don't allow their technical targets to sway so much. The on axis flatness must be prioritized and off axis must be consistent with every other speaker in the line. The speakers must be linear with a very large range of signals. And each one off the line has to match as tightly as possible to the one before. Again, they have the resources to do this kind of work and are building on the knowledge of Klein & Hummel before them.
Erin said in that interview he's never seen a speaker with an on-axis response within 0.5dB deviation. The KH150 is within 1dB.
https://www.spinorama.org/speakers/Neumann KH 150/ASR/index_asr.html And then the pair deviation is within, well, whatever this is:
https://www.audiosciencereview.com/forum/index.php?threads/neumann-kh150-review.64775/
Recently I realized that the KEF Blade 2 Meta (released 2022, USD 14k) has nearly the same -6dB contour as the KH420 (released 2014, USD 5k):
KEF
Neumann
The economics allowing this level of disparity in price vs. performance are just incredible.
The J&C Troubadour speaker (USD 34k) looks like it uses the same basic coaxial driver design as the Mofi speakers, changing out the motor. I'll bet that the overall frequency response and directivity are largely similar, though tighter below 1kHz, and that they play a little louder with lower distortion compared to the 888 (USD 5k) or the V10 (USD 8k).
Edit: Error in price as noted by
@thewas.