Initially had issues with this unit vibrating horribly while running higher speed than low.   Diagnosed to find out the vent to outside was done incorrectly.   With this fixed, we still notice the fan is noisier than the ratings on the site, and also the vent doesn’t really pull in air from the cooktop except what is directly under the left side of the hood (where the actual fan is located).   Overall, this is a disappointing fan and I’m looking forward to the point where I can replace it with something that actually works.