I get asked this question often during the rainy season, and over the years I have seen a lot of different types of gutter guards, and their performance over time, cleaning gutters throughout Sonoma County.
In most all cases I recommend not using gutter guards, as they can lead to other gutter problems, and there are other more simple and less costly solutions.
Most homes will benefit most from a thorough gutter cleaning and inspection periodically. Time between cleanings depends on the amount of trees close by.
In some cases they make sense, such as areas with many trees close by that drop all year or certain inaccessible areas. If you do decide to get gutter guards, it is important the right type of guards are installed, and they are installed correctly.
Even with gutter guards installed some seasonal maintenance is recommended.