Have had my E1 hooked up to my iPhone 3G over the last few days, with my three main portables (SE530, ES7, PFE)... and my impression for most part is positive.
- The sound is definitely very clean (though I'd guess this is mostly due to the LOD component) and the amp does a nice job of adding a bit of soundstage and more midrange detail and resolution overall.
- Bass isn't bloated like my E3 which is very good. It's not incredibly tight but good enough.
- However, I did feel that it had some rolloff on treble region, which was actually good with harsher IEM's like PFE's but not so much with ones like SE530 and ES7... This makes the amp sound a bit warm overall. I haven't tried these out with my PK2, ADDIEM, or KSC75 yet, but since these are bit warm overall I have no doubts that they'll sound very good with them (as the three that I mentioned are bright and can sound harsh and thin out of HP out).
- Build quality overall is good, this is no E3. But I'm a bit worried about how the cable will be over time, as they seem slightly stiff.
- Absolutely NO RF interference with my iPhone so far from my experience which is very good, as it was what I was worried about the most. I have to have this tested out further though since I admittingly only used these for about half an hr at a time (and I had no incoming calls during each time frame).
- With low impedence/high sensitivity IEM's like SE530's, it hisses more than the iPhone 3G headphone out, but not too badly (definitely not as bad as my two former portables, T4 and Bithead). Once the song is playing this is not a problem at all, but still should be mentioned I think.
- I do think the cord is a bit too long. This is fantastic for IEM's with modular designs (which is well... only Shures... can't think of anyone else) and shorter cords (like my gen 1 PFE) but it makes the overall length way too long with most other headphones/IEM's.
- Hate how the shirt clip is incorporated... since the front is all buttons it makes it very cumbersome to put the clip on without accidently pushing those buttons and skipping songs or altering volume. Remote does work as advertised though.
In all, for its price, I definitely recommend the E1 for anyone with an iPod/iPhone, if not only for the remote and the LOD component of it. The amp portion in truth isn't all that impressive (SQ wise, honestly, I don't think it's a whole lot better than my iPhone headphone out) and may sound boring to some but it at least doesn't artificially boost certain ranges like it did with my E3. I'll probably buy one in black as well when it comes out (as all my portables are black) then probably give my white one away to my sister for her use.