4 stars due to the volume, which in essence (if you put everything in the right order, you won't have a problem, but I didn't think about it and placed it before the RAM). I'm thinking of adding a third fan (at the back) but I don't know if it will be excessive, but I'm considering it...

I have been using it for about 3 years with 2 silent Noctua fans, on a Gigabyte AX370-Gaming K7 motherboard in a horizontal position with a Ryzen 1800X CPU. It works for 5-10 hours per day and the maximum temperature I have seen is 35°C. When the fans are running at a distance of 20cm, I can't hear anything, while the fans from the 2-core and 4-core Intel CPUs would make noise throughout the room. I placed the motherboard in a horizontal position because I didn't want the cooler to hang in the air from the mounts on the motherboard. I didn't want to use liquid cooling because it is neither silent, nor safe, nor does it have a warranty. If it leaks, I will lose the motherboard worth 250€, maybe the CPU worth 500€, and maybe the RAM worth 350€. The RYZEN family is highly recommended, "RYZEN AND KNOWLEDGE IS POWER". Prefer air cooling for RYZEN 7 or 9 CPUs that have 90W-105W, while for RYZEN Threadripper CPUs that have 180W-280W, liquid cooling may be necessary.

After a problem occurred with the Corsair H110i v2 liquid cooling system (reaching 75 degrees in idle mode on the Ryzen 1700X with the fans at full speed), and after extensive research on forums, YouTube, etc., its immediate replacement with the Noctua NH-D15 SE-AM4 seemed like the ideal solution. Indeed, the temperature now does not exceed 30 degrees and the noise levels are very low (almost nonexistent). It is a bulky construction, but I did not encounter any issues with my specific case (Be quiet dark base pro 900 rev 2).

The cooler is on an AMD 3900x, without OC. The case is a phanteks enthoo pro known for its airflow.
At idle, it is around 40c. In stress tests, it reaches 62-63c.
However, in the software I use, which essentially utilizes 100% of the CPU for hours, I have seen peaks of up to 78c, but usually it stays around 70c.
Up to 700 RPM, it is practically silent, but above that, it has some noise. The maximum RPM it reaches is 1500.
Reading on forums that some have seen temperatures of up to 95c on this specific processor, I consider it to be doing its job well.

I used this specific cooler on my new i7 9800x processor (4.7GHz on all cores) and in Aida 64 it reached a maximum of 83 degrees, but during gaming it didn't go above 68. Overall, it's a very good cooler and I highly recommend it, although it is quite bulky... Overall, I am very satisfied.

I installed it on a Ryzen 2700X. In idle, the temperature dropped from 45-55 degrees to 38-43 degrees. In Prime95, it went from 85+ degrees with the Wraith Prism in High mode, making a noise like a vacuum cleaner taking off, to 62+ degrees with the Noctua NH-D15, with a noticeable but not annoying sound. All this with a room temperature of 28-30 degrees.

To say that I am satisfied would be an understatement. I wanted to avoid liquid cooling, which I don't like at all, and all the market research led me to the Noctua NH-D15. It is an excellent air cooler, as long as it is compatible with your case and motherboard.

For the case, check the measurements of your case in relation to those of the cooler. To see that it does not cover PCI Express slots and other vital points of your motherboard, there is a detailed compatibility list on their website, which you can find at the following link: https://noctua.at/en/products/cpu-cooler-retail/nh-d15-se-am4/comp

It is installed on an AMD Ryzen 7 1700X Box processor. Just pay attention to the case you will choose - I have the Corsair Graphite 760T (Window) - and then don't worry! Awesome tool! It only lacks in color options, but it's okay! Extremely low temperatures and quiet. I don't have much else to say yet because I'm still testing and overclocking, but so far I am very satisfied. I consider it to be better in terms of price-performance ratio than perhaps almost any liquid cooling - and without the fear of leakage and the care that liquid cooling requires. Just get a good blower, blow and clean!