I have a decent headphone collection, and I'd say I'd rather get some decent IEMS rather than a pair of koss. I don't like the koss sound or design. For the price of these I got the kiwi ears cadenza which are some of my favorite IEMS for cheap listening and use. I have much more expensive IEMS but the cadenzas are great still.
I wouldn't call them but it for life. My porta pro cables brake after 18th months or so. The warranty gives me a cheap replacement cost to mail them in for a swap. But they don't last too long in my experience.
I still can't believe my plastic $25 Skullcandy headphones from before I got my Sony MDRs lasted me a good 8 years. They sounded average, but the bass was punchy.