Personally I call them "Incredible". I have a Vintage Fisher 500C which in itself has a wide soundstage & detailed transient sound; combined with the HD600 = "Incredible" sound.
I know a lot of people reading what I'm going to write next will totally disagree with me but, I prefer the HD600 to the HD800 & sold the latter. I owned the HD800 twice & will not be buying them again. But I will never give up my HD600s, over my dead body !
Well, I have not heard the HD800s, and to be honest I would never actually pay the amount for one, not because I do not believe there is reason too. I am sure there is to some people, but I heard what headphones like the HD600s can offer at a quarter of the price, and I just do not think the HD800 could be 4x as good as the HD600. Not to say the HD600s twice as good as the DT series but is price twice as much. I just think paying that much for a headphone when there is one that is so good for so much less seems kind of like a waste. Now to argue you against my point I do not know if I would feel this way after hearing the hd800. So this is just pure subjective and I think I understand where you may be coming from in terms of sound as well, I have heard the HD800s a brighter headphone that sounds different from the HD600 and maybe you just prefer the HD600s more even toned sound with that warmth.
Actually, I agree with you it is subjective but the HD600's synergy with the Vintage Fisher 500C is simply incredible. Every detail in the music comes out clear & clean; the highs, lows, midrange, all transient, clear & separate without any roll off. I find & have always found the HD800 to be "artificial" sounding & when I purchased my second pair a few months ago (because my first pair was an early model = sibilance galore) I believed that they may have improved with time compared with the first pair I bought. Well, the sibilance was not as pronounced for sure but … I just do not enjoy the overall sound & they were properly amped (Trafomatic Experience Head One, Vintage Fisher 500C,Vintage Kenwood KA-8006, 70WPC). I also don't buy the explanation, at least not in my case, that I have read many times, that the HD800 is fatiguing because it is unforgiving : well, I don't know about that. In my case it's the overall sound signature that does not appeal to me, period. As I stated previously, the term "artificial" keeps coming to mind to describe it's sound signature. But hey, it's all about personal taste in the end.