Something about this shooting that is so different is the distance Paddock was from his victims. He was so far away, could he even see the mayhem he had unleashed?
At Bataclan or Pulse, the shooters were close enough to look the people they were murdering in the eyes and to see the blood draining out of them. Paddock was 400 yards away and 32 stories high. The people he was shooting at must've barely appeared as ants at that distance. It was almost as if he was detached from the event itself, just spraying lead out into a crowd, oblivious to the carnage it was causing as it landed. At any rate, he was dead before he even knew what the body count was.
I would bet that he had good scopes on the rifles that didn’t have red dot sights. I suspect he spent some time looking through good binoculars or good scopes to see what was happening.