I actually like the sound sig of the ER-4S alot after hearing Jin's at the NY meet. It definitely needs amping as I thought it sounded really thin straight out of my mp3 player, but once I hooked up the Portaphile amp, it sounded great. Too bad I won't own a pair because I thought they were really uncomfortable (the cable is heavy and I feel its weight pulling on my ears). I wonder if Etymotic has every thought of a redesign...