Product review (4 stars): It does what it should do.
We recently purchased a new washer and dryer.  With the old dryer, we had been using a similar product as this one. With the new dryer we really wanted to use the exhaust duct. However, we have an older house and it appears that it doesn't exhaust to the outside but to the attic.  That won't work - so back to this product we went.  Before we had quite a bit of dust/lint which is hard to get rid of.  So this time around I got some vent filters and double rubber banded 1 to each side of the hose. They really do keep the lint down to a tiny fraction (and they can be washed and reused). Using this system I have had very good luck (dryer works just fine and dries quite quickly). I do keep water in the bottom - that also helps. We have not encountered the problem some people have mentioned with moisture on the walls.  Our laundry room is in the middle of the house with no windows - but there is a AC vent - so that might be why.