I have US and UK citizenship and passports. I live in the US. I am traveling to China. Does it matter which passport I use to get visa?
As You live in the US and have US citizenship you'd be best off applying for the 10 year visa in your US passport (You need to be both a US Citizen and a US resident to get the 10 year visa - at least that was the case when i got mine in 2016).
With a UK passport most people receive a 2 year visa.