I haven't heard the E2C's but I own the Etys Er-6, which I use with a Sharp DR7 minidisc player. I don't use a portable amp.
WIthout any amp and without any EQ adjustments, the ER-6 sounds okay and maybe a tiny bit weak. The highs are nice but the bass isn't very full. Once I turn on the bass boost (level 1/3 or 2/3, the Er-6 becomes a phenomenal headphone - the highs are still there and the bass fills out.
I don't have the Ipod, but know that its supposed have a more powerful amp than the DR-7, so that might be good for the Er-6. but I think to enjoy the ER-6 you need to be able to do a bit of bass-boosting on your player.
Walking around is oay with the ER-6. I have had no problem with cord microphonics. But with the foam tips I can hear a tiny bit of thunp from my feet - not enough to be a problem walking, but it makes jogging an imposibility. Great isolation with the foam tips and very comfortable - far more so than the plastic tips which to me are just useless.
BTW the ER-6 is $129 new, but if you look for them used (here on this board) you can usually get them fro $90-100. They are also findable on e-bay, but ebay bidders are not very savvy so they generally go for more like $110-120 used on E-bay.
I'm very curious to hear more from those who have both the ER-6 and the IPOD because I love the ER-6 (I'm only gonna use canal phones from here on) and I'm thinking about getting an IPOD.