OK, the KSC-35/75/Portapro is technically 3 headphones, but I believe they all share the same driver : sure I'll hear otherwise if that isnt the case. What astounds me is how many other models they sell in the malls and department stores, all most of which would appear to be aimed at folk who just need a headset for gaming or call centre work etc. One or two others get a reasonable reception in Joker's epic Portable Headphones thread, but the vast majority appear to be the kind of dross you would normally associate with TDK or Phillips.
Clearly, someone at Koss knows how to make a great VFM driver, but it would appear that they lost interest after the PortaPro. Happy to hear contrasting opinions - this just seems really odd to me.