But it's not just a new level of investment in finding ways to make money as China's living standards continue to rise.
The new broom in the China leadership is ushering in a new era of trust in the relationship - after five years of a free trade agreement.
China liked that New Zealand did what it said it was going to do, Key proudly reported.
Key said Xi was the sort of bloke you could imagine sitting down and having a beer with.
Ironcially, the personal connection was strengthened after an incident at Parliament involving a Tibetan flag and Green co-leader Russel Norman and Chinese security.
It was a pretty undignified welcome to the place and Key later bought Xi a pounamu patu by way of a personal apology for not handling the situation better.
But that's been long forgotten.
Now it's about the future.
The scale of development is huge - Xi said yesterday within five years it is projected that China's imports could be worth $US10 trillion.
He could see a day when 400 million Chinese a year could be outbound tourists.
Key says it is a once-in-a-generation development of a country of such scale.
"It's hard to believe it not going to change the world forever."
It's hard to believe it's not going to change New Zealand forever, too.'