I am against transfer of perks because then it becomes currency. I would suggest potentially being able to trade in a large number of perks, maybe 5k, for a free month of play.
This could be interesting for the following reasons:
1. It is a high enough number that farming would be too much of a hassle and could be easily recognized.
2. It could encourage use of aircraft that rarely get used outside of FSO and AvA.
3. It could give some people the opportunity to earn a free month without bankrupting HTC.
4. It would allow people who don't use their perks for the best aircraft to do something with them.
Just a thought.