Product review (4 stars): Decent quality but HUGE
The build quality seems ok. The plastic does seem kind of cheap, but I've seen cheaper plastic before. As long as you're careful with it when you open the lid (which shouldn't be more than a handful of times a year), I'd expect it to last a long time. My major concern is the plastic dome inside doesn't seem to drop squarely onto its resting place about 1/5 of the time. When this happens, it rests about 1-2 mm off of the upper edge of the vent, leaving an incomplete seal. This can possibly be fixed by filing a bit of the "track" down, but I haven't tried as I'm returning it due to the ungodly size.

It's entirely my fault, but this is a lot larger than the picture led me to believe. I was expecting something about 1/3 the size of the item that arrived. Next time, I'll pay closer attention to the dimensions. If you're mounting this on the back of a house or somewhere where the size isn't an issue, then don't worry about the size. If your dryer vent empties onto your patio as mine does, this unit may just seem a little too big and in the way.