First some obligatory photos: Quick Comments: The earpads are slightly too shallow / too small front to back. My ears don't stick out a lot, but when the headphone is worn on my head, the back of ears hit the back of the pads. This is not particularly comfortable. The photos above show the tangled cable. This is intentional. I wanted to show how difficult it was to deal with the cable. The cable has a mind of its own. It coils up like medical tubing and it looks and feels cheap. The person who decided this cable was a good idea must have been smoking opium. Dealing with this cable is extremely annoying. Life's too short. I don't have time for this shit. HEX is more sensitive than the HD650. Orthos have come a long way in terms of sensitivity. The sound seems to have changed from V1. The HEX that I measured (http://www.superbestaudiofriends.org/index.php?threads/hifiman-edition-x-hex-measurements.870/) seemed to sound softer and more boring and sleepier. These seem to be somewhere between the HEX v1 and HEK in terms of speed and resolution. Definitely more energy than the V1. Unfortunately, the HEX also gets a bit of the HEK's splashy treble timbre. Without a direct comparison of the exact units, I could be full of shit, but my memory on these things tends to be pretty good. This could easily be chalked up to revised diaphragm tuning, production variances, or pads. Overall a neutralish signature with good speed and good resolution. Some issues with treble as mentioned above. Sounds light and effortless as opposed to weightier and tactile of many other headphones (HD6X0, HE-6, HE-500, etc.). Measurements in a bit.