score:6
If you are flying there, then you're looking at the wrong place. Better to check Timatic, which is the source the airline will check. If it says you can't use the visa in the old passport, you will not be allowed to board even if you bring a signed statement from the Ambassador.
However Timatic says you can:
National United Kingdom (GB)
Embarkation United Kingdom (GB)
Destination China (People's Rep.) (CN)
- Valid visas or resident permits in expired passports are accepted if holding a new valid passport of the same nationality. The personal information on both passports must be the same.