@beetlemania, The CS 2.4's measure closer to 2 Ohms than they do to 4 Ohms. As there is a direct correspondence model between static impedance figures and sensitivity, measurements are typically made at such fixed points. I don't agree with your assertion that measurements tell you "nothing" about how an amp sounds. Quite the opposite, I think that while measurements might not tell all about how an amp sounds, some aspects of sound are quite predictable from measurements. Frequency response, impedance, power output, distortion, harmonic content, etc., etc., and when and where they are applicable can give one quite a bit of insight into predictable sound. These measurements also provide manufactures an opportunity to provide consistent results to the end user from sample to sample of a given product. They also indicate in what situations a product might or might not be appropriate. Furthermore, measurements give the consumer an opportunity to discover whether a manufacturer knows and or cares about what they are doing.
The amplifiers under consideration are not inexpensive. Having such a generous budget should probably allow for consideration of more options. That the products under consideration measure as they do, suggests that they might have been intended for other different uses. In other applications they may possibly be ideal.
The quote from Thiel is most interesting. What is the intention of the use of the words "high sonic quality". In my conversations with Jim he told me that when he referred to an amplifiers power output, he was referring to standard 8 Ohm ratings. And, that recommendations for power output was with the understanding that one would be using a quality ss amp that could double down, and that if one was for instance choosing to use a tube amp then one should double the power output recommendations accordingly. Was Jim referring to "high sonic quality" as judged purely by perception or by technical prowess and the sonic consequences? I don't know for sure, but I suspect it's the latter. An amp rated at 100 Watts that can double down to 400 Watts at 2 Ohms would qualify as an amp with more "high sonic quality" than an amp rated as 200 Watts that was heading into oscillation below 4 Ohms, when being asked to drive a sub 4 Ohm load.