There's a term that one reviewer (Marcus at Headfonics) uses that I like very much, and that's "tonal contrast". In the reviews I was reading from him, he doesn't even use the term "detail". Elevated treble produces more tonal contrast, which the brain will easily pick up on (our vision is also highly dependent on visual contrast for object identification), and think it's detailed, because the contrast between tones is greater via the boosting of the harmonics. But more contrast doesn't really improve true detail retrieval, just like maxing out the contrast slider on your TV or monitor won't improve the detail that you get from that screen. Proper balance between colors is what produces good visual detail, and avoids colors being crushed.

The treble peaks on the Takstar (I had a HyperX Cloud which is based on that headphone) make certain types of sounds, like the trailing tones of cymbals and snare drums stand out with greater contrast (that sparkly sound), but when those tones are overemphasized, it starts to affect our ability to perceive other similar tones at the same time, so overall perceived detail suffers. I had an Audio Technica headphone that I modded with different earpads, and those headphones brought out cymbals like nothing else. Cymbals would cut through the mix, and if a song had cymbals or hi-hats, you would know that they were there. They were subjectively pleasing to me, but that emphasis on the air region in the upper treble would obscure details elsewhere in the treble.