The cooler is quite efficient and quite silent up to 800-1000rpm.
The fact that it blows downwards helps cool the motherboard's VRMs and has a nice aesthetic result in my opinion. In fact, some motherboards required this type of cooling for specific processors due to VRM cooling.

The way it is installed is not the best, but it is not bad either.
It requires some attention for those using 4 memory slots for RAM, or if using the first and third slot. The first RAM slot, if the RAM does not have a slim cooler, may slightly touch the heatpipes of the cooler, which is not correct.
In terms of height, you don't need to worry. The internal fan is far enough from the RAM. The RAM I use is GSkill Trident Z.

The build quality seems to be at an extremely high level with integrated rubber at the fan contact points. Very good paint as well.

However, the cooler is very expensive. I can't easily recommend it to someone unless they like it visually. I believe that there are coolers that offer similar performance for less money.

If you have a mid tower and a very good processor like the i9-9900K, in this case, it is one of the few air coolers that will fit in your case and you will be confident that it will properly cool your processor. The case I have is the Corsair Spec-03 and due to its size, I had a serious problem with the dimensions of the cooler I could use. Initially, I went for the Dark Rock Pro 4 and the Noctua NH-D15, but they were rejected due to their size. The Dark Rock TF has such a design that allows it to fit in a mid tower and has the quality to cool a demanding processor. The motherboard that houses it is the ATX Gigabyte Z390 Pro Aorus and so far, after 2 months of gaming, it performs excellently. Its design allows space for installing RAM (preferably low-profile) in all 4 slots if needed. The temperature under normal use is 30-35 degrees and in gaming (2K 144Hz), it has not exceeded 65 degrees in the summer with room temperature not exceeding 25 degrees.

Now let's move on to installation:
If you are installing an air cooler by yourself for the first time, it will definitely take you 30 minutes or even more to install it. If you have done it at least once before, I believe you can install it in 15 minutes. The times mentioned above are with the motherboard outside the tower. Inside the package, it includes thermal paste, which I used, and a German-type key to loosen the 4 screws on its base.

Noise:
Due to the 6 120mm coolers that the case has, despite being silent, there is some noise (which doesn't bother me), so I can say that I don't hear the Dark Rock at all.

Build quality:
As soon as you hold it in your hands, you will understand its quality. It is well-built and sturdy in its design. It is relatively heavy and not something fake.

Finally, I can say that I am very satisfied with its performance in relation to the money I spent. Sorry if I tired you, I hope I helped someone.

For this cooler, which I recently installed on an i5-9600, there is good news and bad news.
First of all, praise and honor to all those who mention that they installed it on an already assembled machine, replacing another one.
Its installation is not easy, no lies. A large cooler on its own, it requires effort with the damn little key that you find on the memories - which you must have installed because if it goes in, then forget it. Additionally, the little leaflet with small pictures at the edges of the text doesn't help either!
It's really absurd! Why? ... and here the bad news stop! ... because as soon as it goes in and starts working, you truly understand what you bought! It covers the entire area of the processor, cools the memories, self-regulating the speed of its two oversized fans, giving you the feeling that it does it effortlessly, calmly, effectively, and above all, silently! The processor is clocked at 4.6Mhz and reaches a maximum of 35-40 degrees.
The first Be Quiet product I bought and I would highly recommend it

This specific cooler is simply amazing!

The quality of Be Quiet! products pleasantly surprises me with every purchase, and I have started to believe that while they are at the same cost and build quality levels as Noctua, they are a step better in terms of cost and slightly quieter.

Very nice and high-quality construction, supports almost all types of processors, even older sockets like Intel 775 and 1366, provides satisfactory cooling for VRMs, North Bridge, and South Bridge as it is placed right above the heatsinks surrounding the CPU socket, with bases made of anti-vibration material for the two fans, but the installation could be a bit easier. Starting with the struggle to fit the (2X 135mm) fans and ending with the acrobatics required to install it on the motherboard. However, the result is so satisfying that any complaints are immediately overlooked!
With my PC next to me and the fans at 100%, I can hardly hear anything, except for the air movement!

Everything needed for installation is included in the package, with brackets for various sockets, Be Quiet! thermal paste, and a short, black PWM Fan splitter to connect the fans to the "CPU FAN" pins on the motherboard.

***Before proceeding with the purchase***

I have installed it in a Silverstone LC20B case that can accommodate coolers with a maximum height of 135mm, and it fit without any issues, but check your case manufacturer's page just to be sure.

Visit Be Quiet!'s website (link at the end) and check if your motherboard can accommodate this specific cooler, as motherboards with bulky VRMs, NB, SB heatsinks may interfere with the cooler or prevent its installation.

Also, RAM modules with large heatsinks and bulky decorative LED may also encounter issues, so prefer regular or low-profile RAM.

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Link for motherboard compatibility check with all Be Quiet! coolers:
www.bequiet.com/en/motherboardcheck