Ok some very quick impressions after some casual listening and comparing tracks to my xba3.
In short I am hard pressed to tell the differences between them, they are extremely similar, at times I feel like the H1 may have a richer/fuller sound but then I feel like the xba3 might be a little more clear, then I think they sound the same.
Its gonna take a veteran to really point out the subtle differences between them, Im gonna keep listening to them tonight and tomorrow and then go back to the xba3 and see.
So how are they? Great! They have nice clear bass, the highs are nice, the detail is very good and separation is good as well, the soundstage is good, maybe better a tiny bit than the 3? One thing for sure is that these things go LOUD! I can listen to my 3's max right now, the H1's? Hell no, they are LOUD lol
If you have the xba3 or 4 I dunno if this is an upgrade, if you have a cheaper iem these will be an upgrade, one thing to note is that the xba3 debuted at $300, these are $150, that says a lot.
Someone asked about the re400, its similar to what I have to say about the xba3 vs re400, the H1 has punchier bass, better clarity, better soundstage slightly, about the only thing the re400 beats either are in detail and thats slightly.
As for build/comfort/isolation/looks:
They look great! The red/black is neat, they are a bit beefy, thicker than the xba3, seems like they are about the same as the xba4.
As for comfort they are ok, they fit great and snug for me but keep in mind so do the xba3 which some had trouble with so take this with a grain of salt, I think the 3 is more comfortable to me as of now but lets see.
Isolation is great just as my xba3, about the same I say.
As for build they are plastic but feel very well made and strong, the cable is serrated and im sure will hold up, the jack is the same as the. 3 which is a good thing.
So if you have the xba3 or 4 is it worth the upgrade? As of now, no; perhaps with more time my opinion will change but they sound very very similar.
Re400? I like the sound signature of the sonys better but thats preference but build quality is no question, if build is important to you the sony is where its at.
Coming from a $60-$100 iem? Chances are yes! Just as the xba3 they are fantastic iems which are very well rounded, great for all types of music and enough bass for most people. So worth $150? Yes, no question.
Will I keep them or stay with my xba3? I will put a bit of time into these and see how it goes then decide.
Hope this helps, not the most technical as I am a bit of a newb to the headphone world but I tried my best. Any questions hit me up.