[stomachmonkey]

Had them on my house in the NE.

As noted above pine needles and fine particulate will pass through the guards and form a "muck" that does require yearly cleaning.

We also had a heavily wooded lot.

For me that meant during the fall the gutters would fill with leaves weekly and with high rain amounts they would overflow into the stairwell for the utility basement and the drain just could not keep up with a wall of water pouring down there resulting in a flood.

I had them simply to keep the gutters clear during the Fall.

Cleaning once a year was better than having to get up there 10 times a year.