Product review (4 stars): nice range hood, tricky to install
This range hood is good looking and draws well. It is as quiet as advertised when operating on the lowest setting, but is fairly loud when running full blast. The lowest speed does not open the back draft flap on the external ducted vent on the outside wall, but the higher ones do. Preparation for installation requires a fair amount of assembly of the internal parts, one of which is a piece of plastic to block the exhaust to the room when an external duct and vent are used. (It can be used without external venting, with the air just going through the filter and back in to the room.) Either this piece is not tight enough, or there are other air leaks, because some air is vented to the room anyway. I plan to disassemble the unit and tape up as many internal leak sources as I can find, including the vent to the room in hopes of reducing this leakage.

It took a while to see how the internal blocking plastic piece should be installed. It just slips into place, but that was not obvious. The tech on the help line knew exactly what to tell me to accomplish this step.

I am not an expert, but this unit seems as effective as can be obtained without building a huge custom hood. It is also probably as quiet as can be made.