ORIGINAL: wings
Just because it has an additional servo doesn't necessarily mean it takes another channel. Two of my planes have a servo for each aileron, but are ran off the same channel.
When/if you want to move into competitive aerobatics, you will *need* to have one aileron on chan 1 and another on chan (5/6/7/8 depending on your radio) or you will never beable to mix in aileron differintial.
BTW, I bought a 6EXA as my first radio, now I am regretting it daily. Its a wonderful radio for the casual sport flyer, but limits you on planes like a pattern plane.
I'll be upgrading to a 7C or hopefully a 9C this winter for compititions next year.