I just run these out of my iPhone 7 Plus, nothing high end source wise. I've used both the bluetooth and wired cables. Found bluetooth to sound better than I thought though not quite as loud as the wired option which isn't surprising.
I've changed the tips from what I was using (Westone Grey Plastic) to some Shure Olives and I've run them in a bit more. Sound has improved markedly - I have a feeling this is down to the tip change other than anything. I still won't call them highly resolving, but for their price I'd say the performance is pretty good - I guess I was expecting more based on some of the comments in the thread.
Sound is different to the SE215... Hard to describe, the sound isn't dark but there is a good deal of bass - better controlled than I initially observed, yet the treble sounds pretty extended though not at all harsh or peaky. I wouldn't describe the midrange as forward which is a notable difference from SE215. That initial sentence may lead you to think they are V shaped but that isnt the case. They are actually pretty balanced overall. Simply put I'd say it has deeper sub bass, less forward mids and more extended treble compared to SE215. Sound stage seems wider than SE215 too. Haven't listened to SE215 in a couple of weeks now so that's commentary from memory so take it as potentially biased.
They fit me just as well as the Shures, if anything they isolate sound even better as I find the nozzle goes deeper in my ear canal, sImilar isolation to my Westone W series iems - i.e. v good! The iems are a reasonable size, if I were being picky I'd say they could be a tad smaller as looking inside they seem to have a bit of dead space.