Personally, I have a really hard time ranking my headphones these days, as my music tastes have expanded and my sound preferences are not as specific as they used to be, so that I can now accept and appreciate a wider range of sound signatures. I am now also of the opinion that technical ability is more difficult to evaluate than many think with all the biases that we have. All I can say is that Hifiman HE-500 seems to be the most technically capable in most cases, but not always with Beyers DT880 600 Ohm competing very well with them in some ways. Overall, the HE-500 seems to be my current favorite though and the best headphone I owned overall, followed by the DT880 600 Ohm and UE600 tying for second place and RE262 usually coming up third. I don't really listen to the rest of the 'phones I own anymore, so I don't feel like ranking them, but my modded HD555 is still a solid 'phone to me and KSC75 never fails to surprise me for its performance ratio and sounds more fun the the technically superior, but somewhat boring HD555. The Mb Quarts are good for closed cans, but not as enjoyable as KSC75 or HD555 to my ears. Oh, and the RE0s - well, they broke again.
The build quality is awful on them and I won't buy them anymore. If I was to rate their sound though, I would place them slightly below RE262 overall and perhaps on par in some cases as they have very different sound signatures.