Product review (5 stars): This vent hood is awesome! I had my doubts if 600 CFM will ...
This vent hood is awesome! I had my doubts if 600 CFM will be enough (VH claims it is 900 CFM, but this is is an arguable statement), now I can say it is more than enough. Even with one motor on full speed (300 CFM) - it is very efficient. It is very quiet (far beyond expectations expectations). It is also very nice looking, I feel like there is no longer a need to update our kitchen :) The airflow outside the house is so strong, I felt like it is going to rip the vent louver off the wall :)

Installation details.

This vent hood was installed instead of the old 30"x18" microwave which was claimed to have 300 cfm of suction power, but in reality only delivered noise and no suction. Vent fitted perfectly, leaving 9" of unfinished wall, which will soon be covered by stainless steel back splash.
The vent requires 8" duct, and I had 6" duct, so had to enlarge the hole in the wall from 6" to 8" (this was done from outside of the house, using hammer drill with concrete bit - drilled lots of holes in 8" circle, then connected them with chisel).

Some of the issues encountered:
- Could not hear the difference between speeds on two-speed motor. This happened because the plastic flapper collided with damper valve installed  in duct. I removed both plastic flappers to resolve this issue.
- One-speed motor was making strange, sort of "grinding" noise - this was because the blower wheel was not tight to the motor shaft - this is a fail on Vent-A-Hood part.. I can imagine how much grief this can cause for an ordinary person, who would had to call Vent-A-Hood, arrange service man to come over... some people probably wouldn't even realize that something is wrong.. Anyway, I used allen-key to tighten the wheel to the motor shaft - that resolved the issue.