Great, you'll see ''JAP-FI'' soundsignature is very different of ''CHI-FI'' one!
With all E serie....I feel they are all my genius childs and just can't choose a real favorite one right now....some day I think its the E2000, other E3000 and other E4000. The change in sound ,or more likely in timbre and soundstage, is very subtle, and i even suspect they perhaps all use same drivers (???)...but its a good thing in fact, making the budget E even more great value. As well, I did not have any iem that suit me for sleeping....especially for sound, now, I feel more than satisfy with the E3000 and 2000, as you say, they are extremely small, as if just a single BA was fitting tighly in there.
Very curious to know what you think of them!