Since there was a lot of talk about the Sennheiser hd6xx series, I thought I would add my thoughts, I really like my hd6xx as a nice complimentary companion to my Grados!
For music I use the hemp for pretty much anything, but for music that doesn't require energy and instead can make do with a more relaxed sound and a meatier low end, then the darker sounding hd6xx is hard to beat, an example of this is certain folk music like Eivor, Myrkur and the like, or even synthwave, these all sound absolutely magical with the hd6xx with tubes or the spark(I still like all of these with the Hemp/spark combo, it's very versatile).
Also the HD6xx is probably unparalleled for movies and tv shows, where with the HD6xx you don't ever have to worry about anything ever getting too bright or sibilant.
In regards to a "live" sound; I find the Hemp more live sounding in comparison to the HD6xx. While the HD6xx does have amazing mids, the highs and the low-end don't contribute much in the way of a "live" sound as much as the Hemps do imho. But for a dark smooth relaxed listen the hd6xx is amazing but can sound dull depending on the track as a result.
Btw Myrkur's album Folkesange is giving me goosebumps listening with the Hemp spark combo, her voice sounds so real and the violins and cellos are rendered so beautifully.