Out of the box impressions are positive. The tonality and timbre is pretty much perfect to my ears and they match my studio monitors pretty closely. Natural, effortless, analogue, musical sound. I am particularly impressed with vocals, both male and female, as they sound exquisitely realistic and natural. The sound overall lacks a bit in dynamics and weight, and bass is on the soft side, not very punchy, sub-bass is not particuarly present either and not rumbly, the texture is vey good though. The treble might be a little smoothed over but I wouldn't say they are dark and are tuned very well (I am sensitive to that arrea though, so a little roll off goes a long way). They sound quite airy though! The midrange is excellent and is thier strongest suit. Separation and technicalities are pretty good, adequate, though slightly on the melded, gray background sound. I find these headphones really good at immersing you in the music and just making you listening. My only criticism is really just the soft punch overall, but overall musical tonality deserves much praise. I prefer them to the Sundara in that regard; while that headphone is supeior technically, it is not musical and the timbre of the Hifiman is cold. They do sound quite close to the R70X, though the Audio Technicas certainly have more punch and sub-bass. I think I prefer the Planar's timbre slightly overall. Comfort is decent; the headband is malleable and so clamp can be adjusted, unlike the Sundara! Build quality feels solid.
EDIT - whether I am keeping these or not remains to be seen however. I am a little worried about long term comfort with my pointy ears lol.