By no means am I an audiophile, but I feel I can still appreciate the sound of some good 'phones.
The NVX's are extremely comfortable to wear, even for long periods of time and with eyeglasses (I'm an all-day wearing of my specs so this was important!). My ears never feel sweaty or like my skull is weighed down while they're on. They're actually a pleasure to wear!
They feel sturdy so far, but I'm not rough on any of my possessions so I can't speak for how well they'll stand up to drops and such. They're bulky though and not exactly the greatest things to wear around in public. The XPTs are large and noticeable from far off, but if you're okay with that these babies are more than worth that small shortcoming.
As far as sound goes, they seem very balanced to me. No single tone seems to outshine the other at any point; the bass is warm but not loud, vocals shine but aren't overpowering, and you can definitely hear every instrument in a song without any of them feeling muddied or muffled by another. The bass is clear in rap songs where it's needed and invisible in songs where it's not, which is another huge point for them. In all I love these headphones and feel like I couldn't have made a better choice in buying them.