The difference between the end of ME and ME3:
When I met Vigil on Ilos, it was incredible. It felt like I had discovered something so priceless it could save the universe. The Vigil VI moved and glitched like you'd expect an ancient software to behave. The music matched the mood. I wanted to know more and more, I must have run through all the dialogs 2 or 3 times each to get a grasp on the events.
When I met the catalyst, I was thinking "who the fuck are you, what the fuck are you talking about and when can I get back to playing Mass Effect 3?"
But it was already over.

(((