I have been using these specific headphones for 2 years, almost every day, with each use lasting about 2 hours.
Build quality:
From the moment you open their packaging, you can tell that their build quality is high. The plastic and metal elements are of good quality, the headphone cushions are soft and comfortable, and the opening mechanism is sturdy. This is also confirmed by my own use, as after 2 years, apart from normal wear on the ear cushions, I haven't encountered any other issues.
Comfort:
As mentioned before, the headphones have ample material support in the areas that come into contact with the head, and combined with their relatively light weight, they are suitable for several hours of use. The negative aspect I noticed during my use is that they initially bothered me in the area around the ears, although this doesn't necessarily apply to all users.
Battery life:
I have been and still am impressed with their battery life, as with my conservative use, I forget when was the last time I charged them. The manufacturer claims a battery life of 40 hours, and it is one of the few devices where I can confirm this claim. Additionally, they support fast charging, which although in my experience doesn't correspond to 3 hours and 5 minutes, it still gives you the assurance that you can have them with you constantly when you need them. Finally, the connection with my Android phone is stable, and the range, which doesn't make sense to mention in meters, as every space is different, has never been a problem for me.
Sound quality:
Perhaps the most important aspect when choosing and, of course, paying for headphones of this kind. The sound is detailed and the instrument separation is satisfactory, meaning you can distinguish the placement of instruments in space. The headphones, like the other models from the company, emphasize the bass, which often overshadows the mids, while the highs, although reproduced clearly, are not the best musical experience I've had (I own the Sehnheiser Momentum and the Audio-Technica MX50).
In conclusion, I believe that the most important thing is to purchase these headphones with an awareness of what you are getting and especially what you are paying for, in the sense that there are indeed more musical headphones in this category, like the two I mentioned earlier, which are more suitable for the music I listen to (acoustic rock). However, the Solo 3, besides having strong elements such as their aesthetics, battery life, and bass performance, at the price of 170 euros that you can now buy them for, are a reliable solution.
I hope I helped