Is this on the side with the mic? Either way a buzzing sound like that is usually a failing connection most likely btw - but especially if it's on the mic side, typical point of failure. If you wanted to keep them you could try re-cabling them, but it really depends where the break is as to how hard/annoying that might be - if it's in the mic though you can just lop them off above that.
As for IEMs... of your list I only own the KZs and the Urbanfuns, and I haven't a clue what the JBLs sound like, so ... yeah take with a grain of salt! But I do listen to plenty of rock and for that:
- I tend to pick the ZS5s for low volume listening - a lot of my listening is done at pretty low levels, so this is more often the case for me.
- And the Urbanfuns for higher volume listening - they sound pretty lifeless at low volumes to me but quite amazing when I want to crank things up a bit.
- I feel like the ES3s could sound pretty nice, but mine were broken and badly tuned, and while the broken issue seems pretty rare, the bad tuning seems more common (which is fixable but annoying). Too much bass for me though so I didn't bother replacing them.
As for old pop I find myself picking up the Urbanfuns (or some modded Seahf AWK-009s more frequently honestly) personally when I'm in that sort of mood, but that's not that often.
Also the included tips on the Urbanfun are... not a great experience imo, and I have my doubts how long the cable will last before needing to be replaced, but the IEM itself is built like a tank. I can't wear them comfortable over-ear though, so microphonics are a pretty big issue when moving around with them. But while I find myself picking the ZS5s more often for my music tastes, I find the Urbanfuns more versatile for other things like TV, movies, podcasts, etc, if that matters at all.
PS: All of my commentary is regarding the ZS5 v1 and Urbanfun v2, I have not tried the ZS5 v2 at all, and I only listened to an Urbanfun v1 very briefly well over a year ago.