...just trying to help here and be friendly. Here's some more help if you want BNF (and whoever is reading, of course)...
I gave a good long listen to the HE500s for a while tonight and recommend them highly. I forgot how much I like them. They kind of cast a big field of sound that has a live element to it that's just plain thrilling. And they are very comfy to me too, and I could easily be fooled into thinking they are $1500 phones, so I would buy them with no hesitation. They are actually pretty good to excellent with the stock cable, but I think Drew's Moon Silver Dragon is the best for them. (No, not trolling for Drew, just think the world of his cables.)
The sound reminds me of my old Apogee Stage speakers, not hyper detailed but sort of like a big tall rectangular stage right in front of you with a very clear but not sharp sound,
and an in-the-room feel with real speed and NO overhang. (They're great on percussion especially. Lots of impact but not painfully strong.) There is kind of a unique Hifi-man sound signature that is beguiling. Forceful in a completely natural way. I feel they are easily in the league of HD800s but with a totally different approach. (And they are also up there with TH900s IMHO, but again very different than the dynamics.)
So good luck BNF, thanks for the work on the analysis, I enjoyed it, and I think you should absolutely go ahead with the HE500s. (And don't be swayed by some comments about their build quality or comfort, I think the build quality is great and they feel sturdy and thoughtfully assembled and I never had a problem with them or my previous HE6s, and I think the fit fine with no annoying pressure and I use the standard pleather pads.)