They actually work as advertised!!. We have large fir trees over the house and usually had to clean our old gutters every couple of months. We had new gutters installed with the Master Shield system and had clean-outs put on our downspouts to monitor how much debris was flowing into our drainage system. After a number of large storms, there is nothing in the clean outs. The Master Shield system is doing exactly what it said it would do, taking all the water from the roof and keeping the gutters absolutely clean. Great product.