I've had my DCA Stealth for about half a year. At no point during that time, have I reached for the EQ on my ADI-2 DAC, which was otherwise a nigh-daily occurrence with my HD800S (always felt the urge to tweak things a tiny bit here and there, never quite happy with them). I feel just as happy with the Stealth now as the day I got them, they just sound so "correct", no matter what I'm listening to. I genuinely cannot put into words just how happy I am with them, as sappy as that sounds...
(For what it's worth, I would probably have been (almost, probably) just as happy with the DCA E3, but the irrational part of my brain would have complained about the (very likely completely inaudible) extra distortion that it has compared to the Stealth.)
I also have a HD600, which I will never part with. Absolutely fantastic pair of headphones those are, despite their obvious deficiencies.
Besides that, the Focal Clear (the original, not the MG) is one of few headphones I've ever regretted selling. Despite their deviance from neutrality, they did some things very well. They had a sort of in-your-face energy, that works really well with my genres of choice (mostly Metal and Rock, primarily Progressive). Alas, I sold them for a ZMF Eikon at some point, which, admittedly, didn't end up working out so well for me.