paul says:

I haven’t seen the foam rubber covers but I have tried the screen type both plastic and metal. They only work if you do not have many leaves. You also need to remove them and clean the gutters every year. Bigger leaves like maple block them up fast while oak are not too bad. If the rubber is a dome like device it may work better than the flat plastic. Make sure they are easy to remove since smaller stuff gets in and eventually clogs the gutter. The 3 ft sections are easier to remove but they also allow stuff to enter at each joint. I finally replaced my gutters with large capacity gutters. I also blow out my gutters with a leaf blower a couple of times before rainy season.