I'm afraid I don't have an HE-500 comparison. I think the Talos holds up pretty well against the TH-X00. The TH-X00 is a very formidable headphone, though. In my review I compared the two: Tonally, I think both really nail the targets they were trying to do. The TH-X00 nails being a bassier headphone while the Talos nailed the v-shape. Both are very resolving in the treble, although the Talos is brighter. I think I have to edge the TH-X00 in mids and bass quality. I think the TH-X00's bass bleeds a bit more into the mid-range, whereas the Talos remains more tastefully punchy with less bleed. The Talos rolls off more in the sub-bass, though. Comfort-wise, it's a slight edge to the Talos for me. The Talos weigh more than the TH-X00, but the pads are much more comfortable on my head, and I prefer the Talos headband. The headband distributes the headphone's weight better, IMO, and the pads are deeper and more comfortable overall. My main problem with the TH-X00 is that I'm not sure when I would want to use it. In a noisy situation, it doesn't isolate enough for me to want to use it over a closed pair of headphones. In a quiet situation, I'll never reach for it over my HD800 or some other open headphone.