The RS-1's are by far my favorite headphones. They simply do music "right" to my ears. Great bass, a wonderful midrange, really extended up high with a slight smidgen of warmth, incredible imaging and soundstaging that is out of this world when paired with a good tubed amp, and PRAT up the yin-yang. Throw some clarinet or saxophone and you'll hear the way the instruments were meant to be played and the way they are supposed to sound in real life, no other headphone recreates the woodwind sound so close to the real thing IMO. Strings are godly, you can hear the vibrato from the fingers and the resin layering against the string, with each bow stroke clearly defined and you get a real sense of the player digging into the string. Voices are pretty awesome too, almost a lush-like quality to it.
In my experience, RS-1's have better lower level resolution than even the vaulted hp-2's. RS-1's are surprisingly very refined and have great sonic ability on my rig as well, right up there with my hd650's in terms of pure sonic ability. Good recordings sound amazing, bad recordings sound like garbage, hey, its just doing its job, thats all...
Everytime I put on my RS-1's, I get very distinct memories from my college days. My college's recital hall is a small venue that features various woods such as mahogany, oak, some maple, and various other hardwoods that really gives the place a reverberant, lively, and highly acoustical sound to the performances that occur their, such as my vocal recitals that I use to do. When I put on the RS-1's, I can close my eyes and be transported back to those vocal recitals, where my college musical experience consisted of recreating and producing art songs, jazz standards, musical theater, and other operatic classics as well.
I love my RS-1's because they make music the way I like it, they make the music come alive and they remind why I chose to be a music teacher and choir director in the first place.