I have two of these fans. One is in the original ISS, the other is in a modified T/H station.
The T/H station one is reasonably quiet. The ISS makes a racket, and has since it was originally installed.
When it stops working I'll change it out again. I have two spares. One was bought as a Davis part, the other was repaired with a new motor.
As long as it is flowing air, I'd just leave it.
Greg H.