WOW.
yeah, that's probably the hundredth or so "Wow" on this thread. These earbuds are amazing, and provide a sound that is exactly what a tighter-tuned KSC75 would be, albeit with less soundstage. However, so far I feel that the earbuds provide some staging especially in percussions; while not anywhere in the hi-fi range, there's a unique sort of "separation" that I feel when listening to anything with a lot of drumming.
It's already been said over and over about soundstage, but the PK2 trumps the PK3, and the PK1 over both. I'm curious about the PK2, now that I've had a taste, but that'll be another two months of saving so that my savings don't fail.
I don't know much about the E2C having not heard them, but hear that they lack life and are a bit thin-sounding. Their only advantage, I imagine, would be isolation; even then, other IEMs of similar price have outperformed them time and time again.
Compared to my Ultimate Ears SF3, they aren't as lean or offer the same musical separation, but offer a more lush mid-range with some full bass. However, with a pair of foamies, the SF3s outpace them overall; you can listen to them in any environment and still extract all the lovely details, but not with any non-closed cans.
However the fact is that earbuds are the most portable and fast-fitting form of any phone (unless your ears are weird), and that's why the PK3s are getting used a lot in favor of any other model that I own. It's pretty much grab-and-go, as opposed to having to take some IEMs out every other half-hour to hear someone talk, or not get run-over by an oncoming vehicle.