II was rather blown away late last night, after I cleared a ferry and a nearby abandoned fort of ghouls. Cutscene comes in, and the empty fort fills up with about 25 Nilfguards (with lots of chests that I sadly couldn't loot without having to kill them all). I didn't, BTW. But a new merchant appears.
Walking back to the ferry the sky was clear and blue, and a new huge Nilfguard ship is moored at the ferry, and the people are thanking Geralt, saying they'll name their babies after him. And you can walk on the ship.
Finally, I see a new fire in the distance. Walk up to it and see it's a huge bonfire, burning all the bodies that were laying around (and now gone).
The reactivity in this game is truly amazing, the attention to details for what wasn't even a quest, really. I was stunned. And the sun was shining brightly afterwards. Nice touch!