After 8 years of using the Fractal Design Define Celsius S24, I saw the processor start to run hotter. It should be noted that it was definitely cleaned once a year and the paste was changed every 1.5–2 years.
In short, it was time for a replacement.

The Noctua NH D15 G2 is a real tool. The packaging, build quality, and performance are on another level.
But what I believe you are also buying when you get a tool like this is the company’s support as well (along with the quality, of course).

So, here’s the deal. You use an air cooler, forget about pump problems, leaks, etc., and sleep peacefully at night.

Temperatures: from 75 to 77 in a benchmark on a Ryzen 5700X3D with a relatively relaxed fan curve in a room with an average temperature of 29–30 degrees.

The cooler is big, yes, but Noctua’s design that makes it tilt toward the top of the case, away from the PCI area, doesn’t create issues like previous models might have.

So, to conclude, if someone wants a top-tier air cooler, with all the accessories, while also having the clearance in the case for installation, there’s no need to look any further.

I have tried many coolers and AIO Watercooling in my life over the last 25 years, this is now my only choice.

After the stock coolers, I was always looking for something better and bought those that ranked very high in comparative tests, from Glacialtech to Coolermaster Hydro, from Thermaltake to Corsair.

Fourteen years ago, I got my first All-in-one Liquid (I think the Hydro H40) with which it was the first time I saw the processor not exceeding 80 degrees, but also dropping from 80 to 40 as soon as the benchmark stopped. There was noise as the radiator had quite dense wavy blades and needed cleaning twice a year to avoid clogging from dust. It was worth it because the processor was 20+ degrees cooler. After 2 years (within warranty as back then AIO coolers had a 10-year warranty), it started to raise temperatures. They replaced it for free, the new one had a 3-year warranty. After 1.5 years, it started to raise temperatures again, they gave me the option to get another one. By then, AIOs only had a 1 or 2-year warranty. I got another brand of AIO Liquid Cooler. That one broke too in 2 years. Every time there was the same problem: the pump failed, and the liquid wouldn’t circulate.

When the seller suggested I get an air cooler for 100 euros, especially after 8 years of water cooling and the perfect temperatures they provided, I looked at them with one eyebrow raised. I read some reviews and eventually got the Noctua D15S (single fan). They told me it would be the last cooler I would buy, and that’s true. I’ve had it for 7 years now, it’s completely silent, does its job perfectly even if it hasn’t been cleaned for 2 years, dust doesn’t settle easily and comes off just as easily, temperatures remain at levels of a good water cooler or even better, and the temperature drops immediately after stopping the render/benchmark/gaming.

So the time came when I got a new PC with an Intel i9, the Intel stock cooler sounded like a hairdryer flickering, and the processor was almost permanently at 100-101 degrees whether the CPU was at 80% or 100% (blender scene editing & rendering). I installed the D15 G2 (be careful with the 3 versions, G2, G2 HBC, G2 LBC), with the perfect amount of paste, the second fan slightly raised to fit the memory underneath, and we are now back in a silent environment, with a maximum CPU temperature of 78 degrees, an immediate drop to 35 degrees after the render ends, zero thermal throttling. Easy installation if the motherboard base has an opening and the back bracket of the processor is visible, as that’s where the back bracket of the Noctua needs to snap in. Otherwise, the motherboard will need to be removed, which is not so quick or simple. Also, due to its size, it doesn’t fit in smaller cases, but that’s not a big problem anymore. Cases used to be smaller. The cooler works perfectly even with just 1 fan in case we want the RGB memories to be visible which might be hidden behind the second fan. Finally, when a new socket comes out and we want to put the old Noctua D15 G2 (for which we paid 150 euros!) in our new computer, we fill out the corresponding form on Noctua's page with a photo of the receipt, and they send us the new brackets for free! And if you lost the receipt? No problem! Just write today’s date on a napkin and they will send you the bracket for free anyway.

(From Noctua's page: In case you've lost the invoice of your Noctua CPU cooler, please write your full name and the current date on a piece of paper, take a photo of the paper next to your CPU cooler and upload it as proof of purchase.)