Product review (5 stars): Best Dryer Vent Made
I have had a number of these, the only drawback I can see, is after about 7 or 8 years the top tends to crack/fall off, however considering the length of service and the quality of the product, that is NO big deal.
It is basically self cleaning, reliable, stops outside air infiltration.

You just cant go wrong,  this thing is light years ahead of a regular vent.