leaf filter or leaf guard?

Here's my experience I used to do about 70 roofs a year for a property Management company including two story and commercial three-story roofs. I was not a fan of gutter covers of any kind that I ran across. we have for some applications I'm sure they work fine. Eventually debris gets under the guards it's a much harder job to do your gutters and the parts will break and your up there trying to replace the screens well it's not worth it. With big leaves on a steep pitch it may work pretty good. Most roofs needed to be cleaned off anyway. Preferred method was backpack blower walking the edge of the roof kicking the leaves out as you go granted this is Oregon a lot of rain and not much snow your results May vary.