I have Gutter Helmet on my Northern MN house (think worst snow & ice possible) and it has been 'up' since 2004. I have pine, spruce, oak, poplar & basswood trees surrounding the house; therefore, needles, leaves, acorns - almost everything you can imagine that would normally clog up a gutter. No problems. HOWEVER -- the helmets cannot control a massive downpour.
The only maintenance required is to take a long handled brush to brush out the little notch from sticks, acorns, etc. I can do it myself with the kind of broom that you scrub the deck wihile walking around on the ground! (I'm afraid of ladders).
At my Florida house - also surrounded by pine & oak I have a different kind of covered gutter - professionally installed. Sort of a 1/4" polka-dot- pattern holes - hardsurface insert to the existing gutters -- and screwed in. I still get some debris - but again, worth hiring a professional. This system with the polka-dot holes can capture more water than the helmet version.
On both houses, to keep the water away from the foundation, I have attached those 4" black vinyl drainage tubes and dug down/burying the tubes to take the water away from the house into landscape 10 feet away, then the next 10 feet have the perforated tube watering landscape. It has helped tremendously.
By the way - those Helmet Gutters installed in 2004 still look wonderful and haven't lost their color. The other brand (on FL house) I think are LeafGuard -- and they are ivory in color and look dirty. Next time, I'm matching the gutters to the roof color! Downspouts can be a different color to match the house.
Source: My personal experience