It's been almost a year of me listening to Zeros (mostly with the great Topping DX1), and now I'm beginning to wonder: what's next, and are there ANY more expensive headphones that make sense, given how damn good the Zeroes are in every aspect of their sound (after a minor DSP correction)? And by headphones I mean any kind, not just IEMs. I also have Hifiman HE-400 (the original, not 400x, 400s or 400i) and I have no incentive to put them on now. I also used to have Sennheiser HD800, sold them because HE-400 are better.