Highly Impressed in Quality
I'm perhaps lucky as I have seen some reviews with disappointment from others. But here is my experience.
Delivery: I received an email for delayed delivery but it delayed for only 1 week. So, I accepted it. Anyway, it was delivered to Japan almost 10 days later.
Initial Impressions: Wow! It's mostly about bass quality. I'm not a basshead guy. But I enjoy bass when it has rumble, texture, oomps, and of course tightness. Frankly, I missed this kinds of bass quality in all my present IEM. When I tried some basshead headphones or IEM, it gave me quick fatigue. 1More triple, SE215, and F9 Pro bass have no quality; Primo 8 has singletone bass; MD+, DM6, EX-800ST have good bass quality in different ways, but E12 Ultra gives really ultra quality in bass dynamics. And it has enough headstage that gives some comfort in long listening. Mids and Highs are neither too much and nor too less. But their quality is good enough and none eats any of others. By the way, it is of course not for critical listening (for that I have Koss ESP/95X and a few other overhead).
Impression after few days: I like the the green tips since bass is tighter. Red one is better fit but it doesn't give that unique sound quality like the green pairs. So far, the only issue is that during travel, I feel like it will fall down any time but so far it never happened. The reason is that I used to wear iem over ear and they used to block my entire concha. But it doesn't give so. Sound isolation is definitely poor. But the sound quality is still good and perhaps it's bass strength is more than that of train engines. So I can clearly listen the bass (just of a little bit less quality). Inside Tokyo trains, usually people don't speak much. So, mids and highs are saved. Moreover, I can clearly hear the announcements (though I don't understand them usually for my low Japanese skill).
Among some good points, no call quality issue, fantastic connection stability (rare in true wireless headphones), and nice design (everything inside the conchas) must be mentioned.
Would recommend to a friend.