[actuator]

It wasn't the US's intervention that succeeded in making it a "non communist" state, so the US failed in its objectives. Just because eventually Vietnam itself decided what path it wants to take doesn't mean, it was because of US.

US is perceived more favourably than China because their war with China was more recent and they have active disputes with PRC threatening island territories in South China sea.

Moreover, US has massive influence in terms of their media and their brands, something which China still doesn't match. Same reason even South Korea has massive appeal in Vietnam.