Hi. I finally bought these excellent headphones 2 weeks ago.
Initially I was a bit disappointed: a year and a half ago I bought the 599s but gave them back because of the exaggerated, muddled bass, but I liked them for their brilliant treble.
Then I tried Robbo's EQ and now I'm happy.

Great job! Love it!
I played with the setting a bit:
I turned the bass down a bit and played with the other frequencies. I tried turning the treble down a bit but in the end Robbo's EQ has the most exciting and real sound. I also tried with the mids but it's more complicated not to do any damage.
Now I'm used to it even without EQ. A different way of listening when you can't use EQ, but still very good.
I tried to evaluate the balance of the headphones with mono sound and had some doubts but I think it was due to a temporary earwax plug. Without a professional measurement it is very difficult to tell. In my opinion the headphones are very well balanced.
Lately I noticed that the headphones were not symmetrical on my head and yesterday I noticed that one earcup is thicker than the other. More swollen. So one earcup is closer to my ear than the other by a few millimetres. I tried squeezing the more swollen one, the right one....Strangely, though, the more swollen one should put more pressure on the ear instead it's the other way around.
Maybe it's just details and it's me being manic but I wanted to point it out. I've thought about changing them but I don't know if it makes sense and I wouldn't want to end up with a model with real flaws.
You can see it from the picture. I would like your opinion.
Thx