The difference though is that this isn't narration... it's breaking the fourth wall. Frank is talking directly to us, as if we were in the room with him and witnessing his acts. Narration is a completely different storytelling device, and could be a third party observer or it could be the thoughts of a character in retrospect. I think it's well done in this series, and it's not entirely done with verbal cues. Frank gives knowing glances to the camera as well, without having to say a word. An omnipresent observer can't give a knowing glance to the camera.
I don't know who's technically right here, and I didn't look it up before responding, honestly I don't care. The fact is that when you break the fourth wall or narrate like this, it is taking you out of the world, and it is jarring for me. I'm in the middle of a scene, trying understand subtext and pay attention to the acting performances and what's in frame for clues and suddenly, mysteriously, he turns to me and says exactly what is on his mind. I don't need to pay attention to this scene because he'll tell me what's important about it. It's either redundant or it's lazy to not somehow work his motivations into the scene. Choose one--exposition and context for the scene or show me the scene. Don't do both.
It's overused and it gets tired fast. I may not be the smartest person in most rooms I walk into, but this makes me feel like the audience is supposed to be stupid. It's less than this show needs.