Hey, I've been silently following your build for quite a while - great job by the way (until you set everything to "Rainbow", then it turns into an over-the-top madness, lel).
Now that I've bought 3-pack ML120s and going to order 3 more, I felt the urge to reveal myself, create an account and ask you guys this... since for some reason I believe you'll have the answer.
So... Let me tell the story first :) I bought MLs to replace my 3 EK Vardar 2200ERs attached to a triple radiator on top. Two of them Vardars have turned into unpredictable screech generators in just a year and a half. The reason I say "unpredictable" is that sometimes they are whisper-quiet, and 5 minutes later they can rev like a buzzsaw, and it doesn't really depend on RPM.
I've googled for a little and found somewhat confirmation to my initial guess which is this: my former fans were attached to the top rad and oriented "upside-down" (i.e. were pushing the air through the rad and exhausting it outside). This "upside-down" alignment applies extra stress to the bearing which may come loose with time (one of the faulty fans' blades indeed goes up and down if I gently push it with a finger).
So - sorry for the long intro - I'm really curious, how are Magnetic Levitation fans dealing with that "head-over-heels" orientation? Since I've already bought them, I'm prepared to hear the truth whatever it is :)
Or is the orientation irrelevant and the fact my Vardars sound like a flat tire means only EK's quality control is not the best? :)
(I know I could rotate top fans and turn them into intakes so that they pull the air through the rad into the case, but first, I can see ML LEDs uncovered by blades if I do that, and secondly, I'm keeping the top of my Evolv case half-open for a better airflow, and there's no dust filter there. So three intake fans there could turn my rad into a thick bar of dust in a few months lol)