Installed them and have had them on for 2 to 3 years. Like someone here said, it can buckle with the hot and cold. So it needs to be screwed in to the gutter at least every 1 1/2 to 2 feet to prevent that.
Positive things are it keeps the leaves and debris out. It totally encloses the gutter so you should not have to get up there to clean them out again. Out of all of the do-it-yourself products, this one is the best so far I have tried. Plus, it is barely visible from the ground. It also has a slight pitch, so leaves get shed by it.
The only negative thing with these micro meshes are little dirt particles from the roof would get in the mesh part, plus if you live in a high pollen area it may cake up on it and clog it, like it does where I live. It was not a huge concern, If I got up there I could take a hose and spray them off. That seemed to help, or if we got a hard rain it washed them off for the most part. Spraying them with a hose still involves climbing a ladder, but it is better than having to physically clean them out by hand. This product is higher quality than any plastic or PVC product or regular screen. It is better than any under shingle, first row or second row installed product sold by the pros. The nice thing is it does not disturb your shingles.
The big advantage is the cost is cheaper than what some of the pros use and it still does a decent job.
Performs Well, Easy to Install, Economical, Light Weight