In China’s market, the application of global positioning system for commercial purposes is the vehicle-borne navigation device. The American GPS products have occupied China’s major markets. Qi Faren said that once China’s Beidou-2 is put into service, it will compete with the American GPS. To the average users, this is an all-advantage affair. China’s Beidou-2 vehicle-borne navigation device will be compatible with the American GPS.
Is "an all-advantage affair" correctly used? Do you understand what is meant here?
I would guess that it means that there is no disadvantage to the user. I've never read that usage before. An English idiom that would mean the same is "To the average users, there is no downside."