One of the draws of this game is that it only costs 14.95. When I see a pay for play model game, it reduces my interest in said game. I believe the model that HTC runs now is perfect. Players can earn perks to fly the uber rides while they learn the game. This prevents the whole inexperienced player getting vulched in a 262 that they paid for.
When ENY is a factor, one side has a significant numerical superiority to one of the other sides. It is hard enough to defend when you are outnumbered 20 or 30 to 1. Now imagine if they all paid for tempests or C-Hogs. Defense would be futile. This would crimp the playability of the game, significantly, IMHO.
I think the system HTC has now is the best compromise possible. It allows players to continue to fight while mitigating some of the numerical superiority. Anyway, those are my $.02.