I would never be loyal to air nz if domestic flying was my main purpose of flying and the prices were hundreds of dollars difference between the two. The flights are so short the service is irrelevant, and the lounges are often so crowded I would rather find a quiet spot in a terminal. The only reason I am loyal is because APD international upgrades make flying BP and PE much cheaper with Air NZ compared to any other airline. It's international flying that makes their loyalty program worth it.
​​