Today I received them.
It will be a lengthy review, so grab a coffee and relax while you read.
As the owner of the Razer Kraken USB (first revision), which broke after 10 years of endless gaming due to the plastic headband, I decided to go for something cheaper so as not to commit to a brand with a lot of money.
I had tried a NOD mouse a few years ago and I was satisfied, so I decided to try the brand again.

Regarding the sound:
While they have strong bass, it is somewhat muddy. I measured frequencies with a sound recorder and at a fixed frequency, it produces some irrelevant sounds at a lower volume.
The midrange is good across the entire spectrum, but the highs, like the lows, have some issues. It's not something tragic, but if you have heard good headphones (no, I'm not talking about my Razer ones), you will notice the difference.
The microphone, based on the recording I made, is simply adequate, with a strong emphasis on the highs, which gives the illusion of clarity, as I read in other comments.

In terms of build quality:
The plastic is of decent quality, nothing tragic, but not what NASA puts in its rockets either.
The ear cushions and the leather headband are a bit hard for my taste, but they don't feel like the faux leather that Razer uses in their headphones.
The top part is just plain plastic without any padding, and it's the worst plastic you will feel on the entire headset.
They have height adjustment for each earphone, without any other customization options... no tilt, no folding, nothing.
The microphone is flexible and stays where you leave it. Unfortunately, it is not detachable.

As for the extras:
The sound card is located on the cable and has 4 buttons with a wheel for volume control on the sides. One button mutes the speakers, another mutes the microphone, another controls the headphone lighting (not the controller), and finally, a button controls the vibration.
The vibration reacts according to the bass and synchronizes with its frequency. It is generally a welcome feature and enhances immersion, especially in movies with many explosions, etc. (think Michael Bay).
The lighting is present on the sides of the headphones in a wheel that jumps between 3 zones and 3 colors (yellow to orange, pink, and cyan) every second. The logo in the center does a rainbow cycle, while the microphone and controller have a steady blue light.
It also has software, which unfortunately doesn't do much that you can't do with third-party software.
The only options are a basic EQ with 5 frequency bands, sound effects like theater, bathroom, living room, etc., microphone volume adjustments, and virtual surround sound.
It also has profile import/export and you can have 4 sets of your own.

Now let's move on to the negatives:
I don't think the plastic of the headband will withstand much, based on how it feels. I hope I'm wrong.
It requires intensive EQ to get the sound right, especially in the midrange and highs.
The RGB lighting is not customizable, neither in terms of colors nor effects nor brightness. Additionally, the controller light does not turn off, as mentioned before.
The cable, although quite long, is a bit thick, at least for my taste.
It is somewhat bulky and heavy, not excessively, but above average.
The software is terrible. It looks like it came from the 90s and doesn't change any settings on the sound card. The only thing it does is change options that you can already change through the operating system.
The surround sound is laughable, inaccurate, and distorts the sound a lot. You will have much better results through Windows Sonic or some other application. I tried it on CSGO and had the best results with Razer's surround engine in combination with 5.1 output within the game.
The volume adjustment of the controller is analog, I would prefer it to send a command to the device to change the volume, like the deafen button does.

That's all from me for now. I will update the review for any future updates.

I bought the headphones today since they were on sale and I had a credit... I was torn between these and the zerogroung okimo... I decided to get whichever was available... And it turned out to be this one... After a lot of testing, I have to say the following and I will try to be as strict and precise as possible... The build quality is average, although they are particularly heavy (even without many hours of use, you feel them pressing or even hurting your ears. At least that's how it is for me) and I don't understand where others saw the good quality. The microphone is very good from what I've been told by those I spoke to, flexible, but unfortunately not detachable. The LEDs play in rainbow combinations, cute. Now, the sound... Particularly loud to the point that if you play a game with a lot of shooting (warzone), your ears will hurt. Decent bass, not great and certainly not bad. The treble is average. Nevertheless, the sound balance and overall pleasant experience. It has a braided cable and a controller for adjusting the volume, LEDs, microphone and headphones mute, and vibration (improves the bass but gives a different feel to the sound). ATTENTION!! The drivers are not available online at the moment for some reason... I contacted the company (Greek) and they said they will send them to me via email... I will update the review when I test them... CONCLUSION: For 35+ euros, there are definitely better options. The only thing that slightly improves the situation is the 2-year warranty from the company. If you find them on sale, it's a good choice if you know that in this price range, you can't have it all. P.S. After several days of use, I can say that the sound is decent for almost any use and the vibration is very effective... I got used to the pressure of the first few days, although they remain tiring for prolonged use... The build quality, as I mentioned before, is average but relatively durable... The sound program significantly improves the use, although there are similar programs that would do the same job.