There are much better systems. The one I am using (for 7 years now with super results) was put in when I had the roof replaced. It is a 1/4 inch stainless mesh that fits over the gutter. It is attached to the rim (with screws) of the gutter and goes under about 8 inches of the last composition shingle. The performance has been super. I have several trees in the yard. No failures. Once in a while I have to clear the build up of debris in the channels of the roof.
This system was for a fraction of Leaf Guard!!!
Come over and see.
Reason of review: Pricing issue.