I've had two brands on previous houses. First was K-Guard. The system worked well. Second was GutterShutter, installed on a house we built in Powhatan. The GutterShutter system is bomb-proof and was a fantastic investment.
Not a fan of the filters. Over time, as leaves and other organic matter breaks down, the holes will begin to clog and the guard becomes less effective. When the stem of a leaf works its way into the hole, it becomes a dam. None of the products are fool proof but I believe the Gutter Helmet / K-Guard version is the better choice.