This headphone feels like a workhorse, has a quality build and with many parts of it being user replaceable and made available by the manufacturer I expect it to last for many years.
The headphone sound quality is very similar to the 770 Pro, especially if one changes the pads to the velour replacement ones (which I did).
With those pads, the comfort is excellent for me, it has some clamp to it but not too much (at least on my head) and the sound isolation is typical for a good quality closed back. I actually gave some of the sound isolation up by this change of pads, but the comfort is significantly better when compared to the stockfake leather pads.
The microphone quality is really exceptional. It has a ton of clarity, fairly natural tone and good outside noise rejection. It also doesn't require a ton of gain (like dynamics do) so any decent interface/mixer that can provide 48V phantom power can drive it with ease.
Overall...the only weakness of this headphone (besides the fairly high price) is the fact that the cable is not removable. It is very thick and solid though...so I'm not too worried about it.