I am referring to the version with the gray fabric. My first chair of this quality, so I have no basis for comparison with similar chairs, but it is extremely ergonomic and comfortable for work/gaming/studying. There is absolutely no comparison with any previous chair I have used, since this product is far superior to the others because it allows many hours of use in comfort.
Assembly: Since it was my first chair in this category, I made a few hasty mistakes and it took me about an hour, but in essence it is very easy - if we ignore the weight issue. I even contacted the distributor, OKTABIT, about a question I had regarding the installation of the support mechanism rod on the backrest, and they helped me flawlessly.
After one month of use, I consider it a fantastic chair both in terms of build/material quality and in terms of features and, by extension, comfort.
Two things have truly impressed me: 1st: with the mechanism it has for supporting the backrest, in a way it massages you through the pressure applied to the spot where you are tense.
2nd: the micro-adjustments in the seat and backrest tilt allow you to change posture depending on what you are doing:

- for typing, for example, I have the seat parallel to the floor and in an upright position with a 90-degree angle relative to the backrest and close to the keyboard
- for RTS gaming, the seat in a nearly parallel-to-the-floor position and the backrest at up to 100 degrees relative to the seat (a slightly more relaxed posture, that is)
- for FPS gaming - tilt at most 90 degrees and with the mechanical lumbar cushion pressing a little on your lower back, while at the same time I have raised the seat to the highest position (this is of course subjective) so the mouse can move quickly over the mousepad.
- for browsing - a more relaxed posture with a greater tilt and the seat raised at the front for a more relaxed position
- for watching a movie - in rocking position for comfortable viewing, relaxed, with the seat unlocked so it can rise
- for resting - backrest all the way down and the seat raised and locked or unlocked.
Again, though, you may want to keep changing positions constantly even within the same session.
I am 180 cm tall and 81 kg and this chair is almost ideal in size for me - if I exclude the width of the backrest, which I would prefer to be narrower so it holds the torso better. I was unnecessarily worried about whether it would be too tall for me because it is made almost ideally for heights of 180-190 cm. For heights above 190 cm, it may not be as comfortable because the seat will be somewhat short in depth and the legs will protrude quite a bit, but it will still be fine. For 175 cm or below, it may not be for someone without a footrest, but they will feel like they are in a comfortable throne. It is completely misguided, however, to describe an XL-size chair as excessively tall when you are 175 cm or shorter. Generally, the ideal height is from 180 to 190 cm, in my opinion. As for the width of the seat and backrest, I am more than comfortable, which means it is also made for broader people with quite a few more kilos. After one month, I see that I would like it to restrain me somewhat in width, so that my torso is more stable.
I should say that the chair uses the synchro mechanism, which allows the seat and backrest to move simultaneously but in different ratios.
Seat: It has impressive adjustability in terms of height but - more importantly - also in terms of seat tilt. What do I mean: the seat can be locked at one height, but you can give it different tilts and even lock it at each tilt! This means that, for example, it can be at its lowest and be parallel to the floor, or tilted in such a way that the front part rises so your legs lift a little, depending on what feels comfortable at that moment. Similarly, it can be at its highest point but - as in my case - your feet can still touch the floor because you have left the seat parallel to the floor but brought the backrest forward, so your torso naturally comes forward and pushes your legs lower.
In fact, you change the seat tilt independently of the backrest tilt depending on whether you want your feet to rest flat, on tiptoe, or almost hang, and all this WITHOUT changing the seat height... For starters, I have it at the lowest setting and when it is parallel to the floor and I am not wearing slippers, my legs form a right angle, meaning they rest ideally. I measured from the floor with bare feet to behind the knees and the distance is 48 cm. The seat depth is also ideal for my leg so that - when I am in a working position - the back of the knee does not hit the seat (important for proper blood circulation). There is a 1-2 cm gap.

Backrest: it adjusts independently of the seat but also simultaneously with the seat. Also, there is the mechanism with the integrated cushion in the backrest, which is adjustable both in height and in/out. You may want it in a specific position one moment, while in 20 minutes you may want to move it one, two, three clicks farther out so that it better contacts the part of your back that is starting to tire - something like a massage, as I said before. It is truly impressive how you change the position of the back cushion depending on what you need at each moment.
The backrest height is around 86 cm and the contact point with my head is around 84 cm. There is also the memory foam cushion, which attaches magnetically at the point that suits you. It also sticks over a cover, which I have spread over the entire seat.
The chair fabric is of very good quality and has the feel of a soft, high-quality sofa.
The armrests are very nice, wide, and very pleasantly firm-soft. They also have amazing adjustability with 3 different buttons. In summary:
- the height is adjustable, they rotate 360 degrees at the armrest base and also 180 degrees on a component between the base and the armrest so you can fit them exactly as you want with additional adjustment.
- they have tilt so you can lean back comfortably or hold a phone/book, etc.
- they move forward/backward so you can get close to the desk exactly as needed and keep the mouse at whatever distance you want depending on whether you are playing an FPS game or working.
The height I usually have them at is 69 cm so they pass under the table base, but they also go up to 76 cm.
The question is how long all these functions will last without problems, in relation to the cost of acquiring the chair. If no problems appear over time, it will be an excellent 10-star product. For now, I am super satisfied and after 1 month of continuous many-hour use I can say it is addictively comfortable.
In the picture you can see the setting for when you want to be very close to the keyboard and mouse for FPS gaming. The armrests are very close to your torso.

After 1.5-2 months of use, as someone who sits at the office for at least 8 hours every day, I have only good things to say.

Initially, in the past I had only used chairs made of leatherette, and now I would never go back from the fabric one. Of course, I understand that leatherette is much easier to clean, but the comfort and how much softer the fabric seat is, cannot be compared. It's literally like sitting on a couch.

The base is very strong and sturdy, with no part of the chair "wobbling" even when you recline it all the way back.

The back and lumbar support really helps your body sit in the best possible posture at the desk, because if you spend many hours in a chair, sooner or later you will get stiff and your posture will "slouch" after a while.

The armrests are not those classic "hard" plastics like on others, but are made of soft plastic so you can rest your arms comfortably on them.

Is it quite a bit of money for an office chair? Yes, especially if we are talking about Greek conditions, for better or worse. However, if you sit at a desk, it is perhaps the best investment you can make in a good chair. It's a thousand times better to pay once and be comfortable for the next few years, than to pay €150 every year when the chair breaks...