On the other hand, if I recall right the internet is rife with customer reports of the Arctic fans having noose spikes / unpleasant hums or resonances at certain RPMs. Lots of people using config tuning to avoid it.

I ended up buying Pure Wings as mentioned. Also much cheaper than Noctua and seemingly not having those issues.

It's funny because I replaced my NF-A14 and NF-F12 because they had hums at certain rpms when used on radiators, and neither the Arctics before them, nor the BeQuiets that replaced them, had that issue.