But don't the measurements tell you how things sound? There are some sites that review solely based on measurements with no need to listen
While I think its interesting to see measurements (they do tell some things after all, or help explain problems), judging a headphone solely by measurements is complete nonsense. I once came across one of those sites, banned it immediately from my viewing... this procedure tells me one thing for sure: they have no clue what they are talking about.
That being said, there's a lot of nonsense GoodNotes around with measurements themselves, such as giving a frequency range but no information on how the limits were evaluated, i.e. do the ends of the frequency range get measured with 3db less spl than at 1kHz, with 10dB (which is already just pushing numbers in my opinion) or ...
Things like SPL (should be exactly defined e.g. dB @1mW @1kHz or dB @1V etc), impedance etc. mostly tell you about technical compatibility, frequency graphs give a very raw overview of the general tuning (but often miss any hint of correction curves or measurement gear used and are therefore often quite useless).
Long story short: nothing can replace the experience of *you* listening to a headphone. Alone the fit to your head makes it sound different... plus there's an unavoidable chasm between numbers and experience: there's a diffuse relation between measurements and experience, but its neither stable nor compatible between persons/headphone models.
Avantone being a professional audio gear company should have good measurements readily available though. And I think they'll provide that sooner or later. Yet an open planar... might not be for me anyway. Generally I don't like how planars present bass, and I only have limited use for open headphones in general. Nevertheless I like their design somehow.
Edit: autocorrect-correction