Just bought Hifidk's fairly unused K601s, and boy, I love these things!
The magic that these do with certain songs is incredible compared to my Beyers. Toumani Diabate sounds incredible, Flogging Molly sounds great, the Dubliners sound great, Michael Hedges's Ritual Dance almost made me clear my bowels with how amazing it sounded. The bass/treble impact that the DT770 Pro/250s had were much more lively for metal and heavier rock, but the K601s can hold their own when it comes to metal / rock even if they're not necessarily the best for it.
I must say that the K601s are far better suited for the Travagan's Red amp than my Beyers, although somewhat shrill highs were absolved with the Beyers upon my switch to the Red and I've been told that the K601s are supposed to be bright, but I haven't noticed anything as of yet!
A lot of people have been saying these are all-rounders, and I can see where they're coming from where this 'phone does amazing things when it comes to certain genres and really only sinks to the moderate level of "good" when it gets to a less suited genre. Not perfect by any means, but for the price, it's very impressive and versatile.
S/N: 14285