I'm not sure what you're saying here. The quote "Really, if measurements were telling us the full story about DAC's they all would sound pretty much the same, so much of what's in the graphs is below the threshold of hearing!" implies exactly the same thing. So let me try to clarify my point. I'm saying that when I apply what I know of psychoacoustics to Amirm's measurements, most of them would appear to be below the threshold of hearing, which is about -10 dB SPL in the midrange and in practice somewhat higher since a quiet room might have ambient noise of 40 dB SPL and research suggests that we can hear about 10 dB below the noise floor.
That being the case, one hypothesis is that not everything of significance is being measured. In some cases, I know this is true. For example, I've mentioned the underdamped filters in ESS DAC's, and it's easy to measure transient response. We know as well what underdamping, overdamping, and critical damping sound like, since we've had a lot of experience. So that would have to be measured.
In any case, in no case have I suggested throwing out the measurements that we have! I wouldn't read this site if I weren't interested in the measurements, and their correlation with what we hear. But I've seen Amrin wonder whether a certain measurement was audible because it was of such low magnitude, and I have the same question. I have to suspect that when we measure something that's 90 or 115 dB down it's audible contribution is insignificant and that when we do hear differences, we're hearing something else. But in many other cases, I just don't know. Is that ESS IM hump audible, for example, on music and with real world transducers, and under what circumstances?
I've found that establishing a correlation between measurement and audibility is a lot harder than some here seem to assume. If you talk to a designer, someone who has spent time in the lab measuring and listening, you'll learn a lot, at least I do. I had a very interesting conversation with John Siau at an AES convention a couple of years ago, for example, in which he discussed the effect of non-linear distortion on the reproduction of piano. I think you'd be surprised at how much there is to learn about what matters, and what does not.