it really depends on what you plan on doing in Vancouver but the hilton in metrotown (burnaby) is a ways away from the center of the city. the airport location is a little bit closer but still far.
regardless of the "value" of the reward, i personally would choose the downtown hampton solely for its location. you won't want to go back to the hotel to freshen up before going out to dinner unless you go out to dinner near the hotel.
otherwise, use the award for another city.