In terms of accuracy, 4S scores 92% vs 4P 86%, which is even lower than ER6 !
But again, score means nothing until you try it, your ears are always the final judge.
accuracy scores are dumb. they are also in absolutely quiet environments. isolation isnt as good at lower frequencies. when you are out and about, you WILL want more bass because noise permeates in that region, so you wont be able to hear the details and it will sound thinner. Why not have that option available, for when you go back to a quiet environment?
i don't really have one... I don't even have an ipod...
I'm a musician, I use headphones in the studio, and am looking for IEMs for live gigs.
I have UM2, atrio and UM1, strangely i prefer the UM1, with EQ it sounds ok. I use a RME fireface 800 audio interface on the computer (not portable!) which has a decent headphone out, and i've made a cmoy as an extra headphone amp, it sounds ok, but not quite as clean as the fireface.
we'll probably start using a couple of cmoys or other homemade amps on belt packs for live gigs, with whatever IEMs we end up liking best...
I built the extra resistors into my cmoy, so it copes fine with low Z phones, and Hi Z phones are not much affected.