The only thing that surprises me on this thread with all the talk of treble, is that no-one one has mentioned how good the HE500's treble is? In my experience of owning both RS1 and HE500 and really loving them both. The hifimans really do wipe the floor with the Grado's in the treble department. Yes the Grado's do add a nice edge when they exaggerate the texture of electric guitar for instance (maybe J Cash's voice too?), but really.. Try listening to acoustic instruments and then if anyone cannot hear which is more life-like and natural between the two, then I'm afraid they must have some hearing damage. I didn't find the treble on the RS1's that bright, but for me it was the hardness that is there in the upper mids and this made the timbre of acoustic instruments sound artificial. I appreciate what the Grado's do but I couldn't say they were better than the HE500's with SQ. I used my RS1's as a fun phone for portable use once I got the hifimans, as I couldn't use them for serious listening anymore.
Well said! I totally agree with this.