Pros:Affordable, great sound, perfect cord length, comfortable when on.
Cons:Difficult to get the perfect fit.
The Bottom Line: Incredible sounding headphones that belie their price. Definitely a worthy addition to anyone's audio-related collection.
Why I bought them in the first place...
I recently bought a pair of KSC75's in preparation for an overseas trip to Asia. I wanted a "cheap pair" that I wouldn't care about wrecking or losing as opposed to my beloved Sennheiser PX-100's that I've sworn by for the last 4 years or so. Bear in mind that in Australia (where I am), my Sennheisers were $100AUD whereas the Koss pair cost about $30AUD over eBay. Imagine my surprise when I discovered I now prefer these to my PX-100!
Now, I knew these were going to be good headphones from all the reviews I'd read, but I was still skeptical they could be as good as the PX-100. They are certainly very different in terms of the sound quality.
The Koss KSC75's produce an excellent, very clear and balanced sound. Different instruments and pitches can be easily distinguished without any overpowering the others. Comparing these to the PX-100, which have a very strong bass emphasis, these do sound slightly weaker in that department. However, that could just be an illusion due to the much clearer treble as the bass is by no means indistinguishable (as it is with many cheap buds). The clarity is by far the winning feature of these headphones though, as every facet and nuance of sound is churned out without any additional noises. This is why I now prefer them to my PX-100's, which unfortunately now sound muffled to my ears.
As many people have already pointed out, these sport-clip style headphones can be a bit of a pain! I have to admit that when I first took them out of the packet I was a bit baffled as to what to do with them. With a bit of trial and error (and googling in between) I finally managed to get a snug fit with the best sound. I don't know how other people have done it, but I find that I get the best fit when I pull the top of my ear through between the clip and the phone until it's very snug (I do this after I've already put them on). Once they're on they're quite comfortable but getting them on perfectly and for the optimal sound quality can be a bit of a struggle. It's worth it though!
Build quality appears decent although not as sturdy as Sennheisers. They are very lightweight making them seem slightly flimsy but so far they have not given me any problems.
Someone else made a note that the KSC75's are great for all genres of music, with the only genre left out being classical as they didn't have any handy. For the record - these are great for classical!