I agree. Whenever I EQ an IEM the sound becomes thinner and artificial sounding to my ears. Whereas the acoustical dampners in the filters (blue and black) sound completely natural.
As for a comparison between the 535 and 846 of which there are posts here ad nauseam. I liked and still like the 535 especially the midrange but not only does the 846 perform better across the spectrum it's clarity, soundstage and instrument separation are beyond the 535 and I haven't even mentioned the BASS of the 846.