These are a remade version of the anniversary K702s iirc. They are considerably cheaper than their Austrian made counter part and are widely known for having an insane sound stage. I see all these people posting about them with a lot of speculation and it doesn't look like many of them actually own them or have heard them. The build quality is fine IMO. They are certainly not built like a tank but, when you're making a 200$ version of a 500$ headphone I think it's to be expected. That said they won't just break from a drop and my pair are still the same as they were when I got them.
I do think that they are great headphones at this price for music but, where they really shine is in gaming. The sound stage really pushes these far and away from any other set I've had for gaming. You can hear everything in any direction and can tell that not only is there someone behind and to your right but, even if they're above or below you. It gives a sense of immersion in any game allowing you to just direction and distance in 3 dimensions more than I have personally heard.
If you're looking for headphones solely for music then I think you can probably do better elsewhere at this price like something from Sennheiser. If you play a lot of games and want something that's also good for music then I think you'll love the K7XX. They're also insanely light making them great for long sessions and the earpads and cable are replaceable too when they wear out. The only critique that I have is that the flat headband isn't great and it may be better than the bumps on the other K7s but, if someone sold a padded upgrade then I would buy it in a second. Once I get it positioned just right it's fine and I don't even notice it but, still.
Anyways, you can usually find these on Amazon for way faster delivery, although they're usually about 20$ more than here.