Anybody telling you isolation isn't superb (etymotic-level) is lying or isn't getting a proper seal. Though, I don't necessarily blame them as the included tips are not very good. The silicone tips are mediocre at best and the foamies included are not the type that you can squeeze and insert, they just reform their shape immediately after squeezing them - very awkward. Luckily, as these are size-100, you have MANY options: Westone tips, etymotic tips, shure olives, etc. If you want the best isolation and comfort I'd suggest getting a pair of ety foamies or shure olives. If properly used and cleaned, each pair should last at least a month or two. If you want almost as good isolation but are on the cheap, get some $0.50 foamies from aliexpress. Hell, you could buy a $10 leather hole puncher and punch holes in disposable pairs of earplugs and they would be better than the included tips. As for silicone, get some Westones (eg. Star tips) or Ety triple flanges if you're a masochist.
These are small and light, so you should not run into any issues there but the comfort mainly rests on the tips you choose. I have smallish ears and, with the original tips, would rate the comfort a 5/10 as I could wear them for an hour but any longer and I could feel them rubbing against my external ear which caused sore spots. When I switched to ety foamies, they stuck out a few mm further thus no longer rubbed against my ear and I could wear them for hours upon hours without "noticing" them.
They sound fine to me. Not as analytical as my old Etys. The bass is slightly exaggerated, though not as much as you may be thinking. Pretty non-fatiguing overall.
Between the phone cable and the braided one, these are sure to last you a few years, at least. After all, isn't that why you are looking at replaceable-cable IEMs? It's however long you think the plastic housing will last, really...
4/5: Everything about them is fine except for the included tips. Beware of hyperbolic reviews saying they are absolutely stunning or that they are garbage. If you are a student or need something to block out noise on the transit, these (and the tips I suggested you get) will do the job wonderfully and will probably get you through your entire undergrad. They are worth the price, but you have to have realistic expectations. These are EDCs, people ... you carry them around in your pocket and throw them around in the gym then replace the cable (not the iem) after a 1-2 years of abuse.