At the end of the day, subjective enjoyment is clearly what matters most, but I disagree with the characterization that measurements are "general info at best."
If you search back to the original hd800 appreciation thread (yup - some of us have been having this same conversation for that many years!), there was a discussion involving a Sennheiser rep regarding the patented plastic that Sennheiser developed for the hd800 cups, to go along with the ring drivers, with the specific intent of eliminating resonances and ringing. In response to critical questions over the choice to use plastic in a flagship product, Sennheiser emphasized that this was the best available material and criticized manufacturers of wood cups, for example, for selecting a material that looked pretty but was very prone to resonance issues.
Given the context, I find it fascinating and awesome that members (and former members) of this community went on to measure and identify minor resonance issues, presumably due to the mesh rather than the plastic, as a likely cause of the lone aberration in the hd800's FR curve. Moreover, based on these findings, they developed, tested and ultimately published a clever solution to this issue in the form of a totally reversible mod, using cheap and widely available foam and felt which, for the most part, preserves the pleasing aspects of the hd800's sonics.
Whether you ultimately prefer the modded hd800 or not (and recall that I personally reverted to stock, but only ever tried the 1.0 mod), these guys deserve serious recognition and a tip of the hat for their time and efforts at raising the bar - both sonically and in terms of fostering increased community understanding regarding why we are all hearing what we are hearing.