All right, got these yesterday and been listening whenever I've had free time. On first listen, I was a little underwhelmed. It wasn't as clear as I thought it'd be, nor was it as immersive. I was tempted to take them off and get back to my 300+ hours GR07. But see, that was all because I was listening to the wrong kind of music, with lots of fast drums. As I started listening to other genres, these started to reveal themselves more and more as the gem I was hoping they'd be.
I've had no problems with the fit and thank the lord no vacuum seal (was dreading that one). I'm pleased with the quality. The cable is not bad. It does have some memory character, and I'm not a big fan of the way it feels, but it seems strong enough to not make me worry about it constantly. The IEMs themselves look gorgeous and well-made.
I feel it would be unfair to do a detailed comparison with my well broken in Vsonics given how early the Yammies are on their burning journey, but I'll still point the main differences so far:
Bass - Yams have more body and impact, GR07 more sub-bass and rumble.
Clarity - GR07 sound leaner and clearer but the Yams are not far behind. That thicker/darker sound does take some getting used to.
Impedance - The Yams are a little harder to drive, I find myself cranking up the volume a couple of notches up my GR07 standard.
Soundstage - GR07 feel wider. Yams do have a more 3D presentation, for the little they give to the Vsonics in width, they make up for in depth. The separation and positioning of instruments also adds to that 3D effect. Don't expect it to wow you like a surround sound system, it's a more subtle effect but a darn nice one.
Treble - As can be expected the GR07 shine in that department, with more sparkle. The micro yams however are not completely shamed, not at all. They more than hold their own, providing me with enough detail, and weirdly on some of my favourite tracks, I've picked up on some little sounds that the VSonics didn't put forward. Some songs sounded completely different on the two IEMs. (Note: I have noticed some hints of sibilance a couple of times during early listening stages, but this is by no means intrusive or off-putting, the GR07 put me through way worse in their days.)
Fun - This is where the yams shine for me. That extra bass they offer, along with the presentation and detailed highs makes for a thoroughly enjoyable listening experience. If the GR07 get my toes tapping, the EPH get me full body up and dancing.
Oops I realise I said I wasn't gonna go into much detail, oh well
To finish let me say that I have absolutely no regrets whatsoever with my purchase. I was looking for something that would work well alongside my GR07, that would provide me with about at least 80% of the sound plus an extra dollop of fun on top. And these more than deliver on that note. Yes, the Vsonics are better all things considered but then again so they should! I paid more for them. I'm starting to fall in love with the EPH and they haven't even completely grown into their full potential. To those waiting to receive theirs, when you first try them, don't expect fireworks right away. Give them some time to work their magic on you and you'll be happily surprised.
One more thing, please be kind when it comes to my comparison/description above, my knowledge of musical terminology is not very advanced yet.
Thanks to all of you on this thread who got me interested in the EPH-100. And my wallet isn't even that mad at you. Good value this is.