That's a tough one. I've yet to see any foreigner with no ancestral ties to China naturalise a PRC citizen. I have heard of many people of Chinese decent who gave up to their Malaysian, Vietnamese , Indonesian nationalities to become a Chinese national. From what I've read, they had some repatriation incentives back in the sixties to get some of the overseas Chinese back to China.
As for foreigners with no ancestral ties to China, I've yet to see any naturalise a PRC citizen. I have however seen an elderly caucasion couple at the Hong Kong airport both holding HKSAR passports so I'm sure they do exist.
There are also many people of South Asian descent who have lived in Hong Kong before the handover and only hold BN(O) status with no Right of Abode anywhere else. Many of these people end up acquiring Chinese citizenship through naturalisation and have no problems in the process.
I'm sure many people from western nations wouldn't mind naturalising to acquire PRC citizenship if they don't need to renounce their foreign citizenships. That's usually one tough dilema to face.