I have narrow and sensitive ear canals. Despite trying every conceivable tip and a few different IEMs, I just can't use the deep-fitting ones. If I could, the ER-4S would have ended my journey here years ago. I found them to be perfectly flat, clear, detailed and natural sounding. Despite trying a tonne of other options I've never found anything quite the same. I'm currently using Hifiman RE-400s, they are not bad but they are less natural sounding and detailed than I'd ideally like. I'm currently hoping that either the VSonic 7007s or the RE600s will be a nice upgrade option for me but I thought I'd post to see what else people would suggest. They need to be shallow fitting universals, under $500 and flat, detailed and natural sounding. I don't mind if they are slightly warmer or colder than neutral, nowadays I tend to think phones can still sound natural with a range of sound sigs as long as they are correctly balanced, and natural is what I'm really after. I would also prefer them to be worn straight down rather than over the ear, but I might be flexible on that. I'm not posting music preferences because I think that makes a lot less difference than a lot of people make out and I listen to a bunch of different stuff. I listen almost exclusively to ALAC files on an iMod, with a Headstage Arrow.