I bought 4 of these fans and paired them with 2× Phanteks fans that came with the case (for 6 fans total – 3× in, 3× out).
The mounting system is great – rubber connectors + washers you just push through the case into the fan (no screws!). The black colour matches the brushed black Phanteks case I have and also goes really well with my Noctua U12S Chromax CPU cooler.
Paired with the Noctua and existing case fans, the system is incredibly quiet – I didn't realise how loud it was until I swapped out the old basic Deepcool fans I had and the Stock AMD cooler. The cables also have a decent length to them, allowing you to run them straight to the motherboard if you wanted, though I've used a couple of 4-port fan hubs on the back of the case (1× each for the intake and exhaust groups) so that I don't have 6 fan cables poking through.
I was tempted to join the RGB hype train and buy some aRGB fans but for the additional price I just couldn't justify them, and I'm happy I didn't – these are amazing. The few RGB lights that I do have in the system cast a really eerie, dystopian kind of glow on the black fans/other black components, and RGB fans would've killed the understated look that I like.
Highly recommended, I'll definitely be replacing the remaining fans which came with my case with 2 more of these when they're back in stock.