The screen type still let in a lot of fine stuff off the oaks, hickorys, MY NEIGHBORS white pine, and my dawn redwood. Don't get screens unless you're putting on a new roof, get the hinged kind, and the installer really does know how to interface the screen with your shingles.
Paid a lot for mine. I thought to meself "get the screw down kind, neighbor he just bought a roll of that stuff (in a post above) and some gutter clips ... picked it out of his bushes all the time after high winds ... put back all bent up & looking like crap."
So now I have professionally installed purpose made screens and commercial grade gutters ... 3/4 full of tree droppings and pine needles that even a pressure wand won't blow out. ALL those friggin screws have to come out to clean the gutters without tearing up the screens.
Moral you ask? Putting gutter protectors up is an attempt to get out of an odious chore. If you don't have a yard full of mature trees .. fine. But if you've got several trees around twice as tall as your house, whatever system you get .. helmet or screens ... has to be hinged or easily removed to clean out what does get through. Since you're GOING TO HAVE TO CLEAN THEM ANYWAY, just get the downspout screens. Then get out yer blower, or hose, or child for labor, an clean them right anyway.