You comparing watching videos to what I played in front of a monitor/TV??? The details in Forza 5 is what is the impressive thing. The amount of things happening in the backround, the lighting off of the cars was impressive as anything I have seen. Infamous was very impressive, but it also had a lot of issues with pop up, slow-down and weird pauses as you played. Again, I have been going to these shows for over 20 years and know not to judge a game with issues this early.
But as mentioned, out of all the games played (in real life, not a video) Forza was top showing followed by Infamous. Yes, totally different type of games and all. But seeing a game at 1080p/60fps with the effects and visual flare that Forza 5 showed was a pretty impressive showing.