This is the problem I had with MoS.
The most important of the two clips is the second one, and it's not even what Superman does when he "lets loose". It's at @0:38 when the collective representatives look on in horror. The day they finally feared: What would happen if Superman played by his own rules? Who would stop the God that saved them from countless insurmountable odds? A God that deigned to listen to them like their opinion mattered as much as a man who could literally punch their planet apart if he had a bad day.
That's the problem with Superman in MoS and what actually makes those clips so thrilling. Because we spent time with Superman. We know his morals. We know his limits that he self imposes. Life could be so much easier to him if he just destroyed those who oppose him. But he doesn't look at his power as the Carte Blanche to do that. He looks at his powers as a huge responsibility he must share with the world.
That fact makes me such an interesting character to me. People keep saying "Good is so boring because everyone's good". Look around you today. Really think about what would happen if any one of these perpetually triggered, "MY OPINIONS ARE UNIVERSAL FACTS" rage machines developed a tenth of Superman's abilities. Do you think they would be selfless? Really? It's not easy to be good. It's not easy to always take the high road. It's not easy to think about the world before your wants day after day, minute after minute.
And we just don't get that with the Man of Steel. We get someone confused. We get someone that we don't identify with as the hero we came for. Almost every bit of his character isn't there. Made almost weak and pathetic by "Maybe you should have let those kids die". It's like if Batman's parents were just lost at sea due to someone trying to force a hostile take over, but him still developing a 'no guns, no deaths' policy. Nothing about his background would have warranted that, but you put it there because that idea comes with the costume. That doesn't work that way. At all.
Superman was not depicted as the center of good that we know, he's not the big blue boy scout... So that's why when Superman killed Zod, it wasn't anywhere near as shocking as people wanted it to be. Because this isn't the Clark Kent that we grew up with. Almost none of his values are there. It's like watching Superboy Prime and being told it's Superman.