I had my first fail in a few months, my second only after a month (feb) and Ive been running it since lol.
My loop was already expanded (second swiftech xp dual rad, ek 290x block, 4 nf-f12) when I got the replacement....it was silent at first for about a month or so. no Issues. then all of a sudden when the rpm would go up to 1800-2000 it would start making the swishing sound then a whining sound.
soon after when rpm would go lower to min it would make noise....definitely not air noise at that point. I found running it at full would get rid of the noise temporarily but eventually it started making noise at any rpm.
So now im sending it back and getting a h220x in return, so hopefully having the pump up top will fix the issues.
having the level indicator you can make sure you don't run the pump dry when you refill and bleed.
can't wait to go back to silence and 10-15 c better performance lol