Plenty of web browsers have built-in (or via extensions maybe) pdf viewers, though likewise, I think the format at IF could be better. Those are missing some information that could be useful; in addition, I'm kind of skeptical as to the value of the square wave plots. Those are mostly just a snapshot of frequency response and phase response, sampled at just certain (arbitrary) frequencies, with some limited CSD-type information on top. The combination of all these factors implies a sophisticated complexity, yet these cast a narrow net, only looking at a small set of particular frequencies. In my opinion the complexity also obscures some of the information of interest.
Anyway, just because the tests result in numbers doesn't mean that there is only one way to analyze and interpret the results. How do you weight the importance of FR vs. CSD, or anything else? (actually, if you want to know an answer, maybe you need to supply an objective function...) For some parameters, I'm not even sure if there is any real consensus or rock-solid indisputable research on the importance and effects, though there is probably more research along these lines than some naysayers assume. I suspect that some few headphone designers out there know more about these things than any hobbyists or journalists commenting and making measurements of their own.
Furthermore, are you looking for the device with the best performance on the test dummy's ears (a reasonable goal, from an academic point of view) or on yours?
That said, if you're looking for a certain parameter only and ranking headphones by lowest THD or any other single category, I think that can be managed reasonably, though still there would be arguments over the importance of the distribution of harmonics and so on.
Taking a very casual approach and eyeballing which seem to do better with some kind of arbitrary weighing, you probably should look at some of the electrostatics (don't forget Senn Orpheus), modern high-end planars like HE-6 and LCD-3, and HD 800. Actually, these happen to be the headphones you might look at based on peoples' subjective assessments. But maybe somebody else has a better list. In many ways, some older flagships or reference models like HD 600 and DT 880 seem to do a lot better than many more-expensive models these days.
Edited by mikeaj - 11/7/12 at 12:36pm