Perhaps not the most outstanding headphone sound-wise, Sennheiser’s good ol’ HD598. This is a model from the era when Sennheiser still manufactured high-quality headphones. I also own the HD6XX, and it is completely different from the HD598.
I feel like I could wear that headphone for a whole month. It is super light, super cozy, and also quite high-quality.
Regardless of which headphones you choose, I think you should go for light velour pads (like the ones on the HD598).
Have you considered an IEM instead of a headphone?
I used a Beyerdynamic (DT990Pro) for a long time and found them to be by far the most comfortable headphone I have tried (the T1 was a little bit more comfortable, but not by much - basically the same build). However even with those, after a few hours, the ever so slight pressure against the stem of my glasses started to hurt.
With IEMs, I can wear them basically 24/7 without any issues (and I often do wear them for 8+ hours at a time). Also they don’t mess up your hair.
…Did you try bending the metal arms?
I would have only taken $300 for that advice, you could keep the other $700.
Any other headphone experience? Assuming light-weight will also be important, maybe suspension strap not critical. Beyer (non-pro) models are pretty comfy for me, but they aren’t the largest pads you’ll find. My SHP9500 and 5xx have virtually zero clamp, light, with big pads — your larger budget allows for better headphones than these though. Harmonicdyne Zeus pretty easy too. The “winged” open-back models from AudioTechnica are interesting from a fit perspective, though certainly not universally loved. They are perfect for some. Very light in weight also.
Sound signature/application wise is there any element that is important?
Try the ATH r70x really comfortable with a sound signature similar to 6xx but imo a little better more extended in bass and treble more neutral and and a slightly larger stage with awesome imaging.
I tried the 660s and honestly find the ATH r70x much better.
Coming from my hd 600 to hd 660s I noticed I was turning volume up and up trying to recover the missing treble, while with the ATH i simply found it an improvement over my HD600 in every aspect.
Simply the Dan Clark Audio lineup. Aeons are 330g planar that have superb comfort. Can’t speak to Ethers, however they are incredibly light for a full size planar at 290g
I keep two headphones out at my desk, and one is always the Philips SHP9500. I keep the rest in a book case in another room.
I typically go open back for headphones, but when I really want comfort, I wear IEMs, which are my workday solution these days. I tend to think of IEMs as my closed backs going forward.