Frank_N_Stein
Grandmaster
If you don't get the angle just right on the systems that basically cover the top of the gutter and rely on surface tension to pull the water back into the gutter, you will have water shooting off the roof at the times you most want the gutter to catch it.
I have had three different roofers tell me that the best thing is to leave it open and clean them out once in awhile. But that is not always practical so I can see putting something up. I had two of them tell me about a screen that works. It is a certain brand. They claimed that the other's don't work as well as these do and only one of the two sold them.
I'll try to find it when I have a little time and post a link.
I have a ranch with a 4/12 pitch so I can easily walk it and blow them out with my leaf blower. But last year before I had two ginormous maple trees taken out, it would clog the gutters during a rainstorm! I could not keep my gutters from clogging and overflowing. Thankfully, they are gone and now I think I can get away with 3-4 times per year blowing them out.
My house has a gambrel roof so it is pretty steep pitch and I was told the solid cover won't work and will cause a waterfall effect. The front and back enclosed porches have roofs pitched like yours so it would work on those. I just need to be more vigilant about cleaning the gutters in spring and fall.