ENY should go bye bye! Should be replaced with an alternate perk system. Using a perk that would allow you to fly "anything" possibly costing you more!
One of the really bad aspects of eny for me was, if it got bad enough there would be enemy jets all over the friggin place yet I couldn't up one. There isn't much as fun as a "jet-fight". It is sad that most all peeps will only up jets when the risk is low. I would routinely up "expensive" jets to hunt "cheap ones"
I say make it so you can fly anything you desire at anytime! Just make it "perk costly" to do so!
Oh as a side note, with such a system I bet HTC could make "BANK" selling perkies for a fee