Any analysis of Obama's speeches has to recognize that he builds during a speech. He usually starts out slow and measured. He's a slow and measured person.
But holy crap, when he gets going...
This convention was a masterpiece of messaging. How many speeches fed into that one.
Also, he did a great job of turning the "Hope and Change" snark into a paean to America's people, not himself. That was a great rhetorical device that was the direction of the entire convention.
UPDATE: The GOP pushback is that Clinton gave a better speech. I personally liked Obama's better, because - while I smiled along with Clinton - Obama's Lincoln reference just gut punched me.
Still, there is an argument that Michelle or Bill gave a better speech.
I don't hear anyone arguing that Romney gave a better one.