Had these for a week and a half now. Amazing sound quality for the price. Obviously if you blast bass heavy stuff at full volume you might not get the best experience, but that's not really what I use these for anyway.
One thing that is not included in this review is the microphone. From what I've seen online, it leaves a lot to be desired, which makes sense for a product of this price. Had some glitches on iOS trying to get calls to go to the headphones at all. Other than that, I don't have anything else to say on the microphone since I never used it.
So why 4 stars instead of 5? Well the product had a few hiccups.
1. The ear clips are not good. Maybe they're good if you want something really tight on your ears for when you're running. But overall they're unusable for me.
2. The foam cushions started to fall off after a week. Pretty annoying.
3. Will allow itself to connect to multiple computers/smartphones at once which causes audio to be wildly desynced from video. Best practice is to make your device "forget" the KSC35's when you're done using it and then pair them up again if you're going to be using the headphones with multiple devices.
I was able to remedy the first two problems by utilizing an old pair of broken KSC75's I had lying around. Replacing the foam cushions and the clips from the KSC75 made the KSC35 Wireless everything I'd hoped it would be. Would have been really nice of Koss to ship this product with extra clips and foam cushions for those who prefer the KSC75's.