I doubt there is anything that is totally maintenance free, like the commercials claim they are. Still, I'm sure some types are better than open gutters.

I have the kind that are completely closed on the top and use the adhesive property of water to flow over the curved edge into the gutter. The edges get dirt on them and cause the water to drip rather than flow into the gutter and I think some Maple seeds flow with the water into the gutter. In my area, it will take a lot longer for the covered gutters to fill up with debris than open gutters would. They do seem to create ice dams in areas of my roof since any melted snow will flow onto the colder gutter topper and freeze. My house is only one story so when it starts getting warm enough for the snow to start melting I go out with a shovel and remove any buildup on top of the gutters. The ice seems to come off pretty easily.

I think the mesh type of covers that sit on top of the gutters would eventually clog with dirt and debris, but I don't have first-hand experience with them. I've seen ones on TV that look like screens and think they wouldn't work for very long without needing to be cleaned.