Say somebody is willing to pay for your plane ticket with any airline you prefer.
1) Pick the airline where your frequent flyer miles are. The airline isn’t too bad; it’s not at the bottom of the ratings list, but it’s nowhere near the top either.
2) Pick a different airline to experience the difference in service. This airline is one of the best in the world.
Frequent flyer points cannot be transfered from one airline program to another. There is a fair difference in the price, but your sponsor is willing to pay extra (but not willing enough to pay for a first class or business class seat).
So, which airline would you choose?