Pacific is fine - maybe not as much backup capacity as VNA if something goes wrong. If timing is critical, maybe I'd choose VNA.
Pacific was set up to give locals an illusion of competition. The basic fare structure is the same as VNA and it will never be allowed to threaten VNA. I believe VNA is actually a shareholder - but I might be wrong. Nevertheless its effectively government controlled. An insider has told me that over the years it will be run down as the government focusses capital spending on VNA in an attempt to compete with foreign carriers.