I got together with several audiophile friends to compare headphones, including these KOSS ESP/95X, classic Grado 1000, Sennheiser HD600, Hifiman HE4XX, Sony MDRV900, and a couple others. Signal came from state of the art Sony transport and AD/DA converter, a VALI tube hybrid headphone amp (which served as a preamp), and a ARTcessories HeadAmp4 headphone amp (which served as a splitter). KOSS were the disappointment of the evening. The detail and sound stage are terrific, as one would expect. But comparatively speaking, they were very thin, lacking depth and low-end impact. None of us were rushing back to hear them. BTW, the Sennheisers were the star of the evening.
All that said, I thoroughly enjoy the KOSS ESP/95X, particularly for movies. But they definitely pale in comparison to other headphones.