I just got my own K701 today from HeadRoom. Fresh-from-box impression: not much better than the KSC 75
Burned in for 3 hours so far using a variety of electronica (the CD is actually a compilation soundtrack for "Wipeout XL"), and the sound has already changed! The highs weren't very present at first, but now they're almost as harsh as on my MDR-V6. I hope that gets tamed down a little.
The sonic differences are
beginning to reveal themselves, and I'm starting to hear subtle nuances in my CDs I've never heard before! The soundstage is also pretty nice, it gives a big sense of "space" to the music as if for breathing room. Appreciable change from my K271S.
Bass doesn't seem to extend very low...yet. Hopefully burn-in will work on that too.
I like the aesthetic design too, I think it looks cool. Very comfortable too, and very lightweight, you almost don't feel them on your head.
On another note, I can't believe I own SIX headphones now! Six months ago I was telling myself I would never spend more $200 on even one headphone!