Product review (5 stars): I will say that the amount of air it moves is pretty impressive. A few things
I bought this item and installed it but have yet to fully test it.  I will say that the amount of air it moves is pretty impressive.

A few things.

1.  Packaging was great.  The item came without a mark on it and I think it was packaged extremely well.
2.  You NEED a rigid piece of duct coming off the unit itself.  I had some semi-rigid 6" flex tubing and there's just no way to attach it.  A rigid piece attaches very easily though after drilling holes in it to match up with the screws and holes in the top of the unit.  I actually went with a 6" to 4" reducer as I don't think it's a powerful enough unit to need 6" ducts.
3.  The mounting options are kind of cheap.  I would've liked to see some reinforcement of the areas on the hood where the screws were to interface.  It's not very heavy gauge material (nor does it need to be) but the points where the mounts attach and all the weight is bearing on it, it would've been good to add a little extra strength in those areas.
4.  It's very quiet and easy to install, but the directions aren't very clear on what you need to do, so it's good that it's pretty intuitive.