I usually avoid first quick impressions due to new toy syndrome but I have now put them through their pace and I will say I am very impressed by those. I have been trying hard to find faults playing various style of music but those are incredibly close to my ideal sound.
My favourite headphone is the HE-6 although as a former bass-head I really enjoy dark and warm signature -that why I love the SD3 and JVC DX1000 so much. The S-EM6 are very similar in overall sound signature to the HE-6, though the treble on the HE-6 is clearly better.
The bass on the S-EM6 extend very low with a very slight boost in the mid-bass but they can nicely rumble and the best quality I heard.
They have very similar lush and forward mids to the SD3 but are quite a bit more transparent and detailed.
The treble isn't that sparkly but somehow remains very realistic and refined. Some people could have issues with the treble as it isn't very pronounced but they never exhibit sibilance, even with my worst recordings.
It is the first IEM that I heard that manage to sound quite open but with great imaging, again very similar to the HE-6's presentation.
I really enjoy the fun sound of the SD3 but those a clearly superior in every aspect, of course, nowhere near twice as good.
Value wise I am not sure where I stand although they are definitely the best IEM I heard so far.
In the end, I would say they are very refined with superb bass and mids, and very realistic imaging.
They are very comfortable and isolate well but I had wished for more more tips choice. I only got medium size double flanges.
I am waiting a bit longer but it is likely all my other IEMs will end up in the sale forum.