The most difficult factor to get from an headphone is a natural timbre...
On par with it the spatial qualities of sound, and with many good public recording an "out of the head" holographical effect when you forgot that you listen headphone as if listening speakers.
None of my past 10 headphones ever did this two aspects right together...
Add to this very deep bass with no booming effect and we lost most headphone at any price...
The best headphone for timbre i owned, save my AKG K340, was the Stax SR-5 gold, but the soundfield was around my head never out of my head and no deep bass at all...
I am not able to recommend any other headphone than my optimized K340 but it is old now...
I would fear buying anything new because of costs and dissatisfaction