Higher energy use per unit of GDP *but*

that is normal. Poorer countries have lower GDP but also do more things with that GDP that require relatively more energy.

(example: Healthcare is 1/6th of the US economy, and relatively low energy intensity. It is a much smaller proportion of the Chinese or the Indian economy).

The question is whether the Chinese use 'best practice' on technology ie where the 2 economies are comparable, are they using as modern technology as the US?

In the typical exporting factory I would say yes. In terms of technology and productivity, the Chinese are up there with the best of them.

In the economy as a whole (including transport, power generation, domestic manufacturing, farming etc.) I would say no. For example their typical design of passenger car seems to be about 10 years behind the US.

One complication in the Chinese economy is that because they don't have a full market economy, the prices of energy may be distortedly low. This would seem to be particularly the case with electric power, but to a lesser extent with gasoline.