Geographically China is very similar to the US, it's between similar latitudes with China being fractionally bigger.
I can't remember the exact figures but China has over 100 cities with more than a million people. The USA has 6. Is that about right?
Economically China has already surpassed the USA (being argumentative now) because it's output is more useful. The USA only seems to manufacture hi tech stuff like weapons and hot air (advertising, media, law etc).
The USA's advantage in communications has changed now as it's population mostly speaks Spanish and the Chinese are speaking more English. Of course this is a double edged sword and speaking Spanish is useful. But I think English still has the edge (but the Chinese are learning Spanish too).
The Chinese political system has some major advantages over the American one, namely long term planning is possible, growth through tax cuts isn't the only strategy going and it doesn't need to waste it's effort on wars so frequently. It also has fewer enemies.