I'm sure this has been discussed here before, but past posts seem pretty well buried now.
I've been giving some thought as to whether rudder or aileron (in isolation of each other) is better for initiating turns via autopilot control. As a bank-and-crank RC flier (it wasn't until relatively recently that I learned that the left stick on my transmitter could be used for more than two things, idle and full throttle), my initial thought was to use aileron. But the more I thought about it, the more I realize that rudder is probably a better way to actually turn a plane with anything less than a 60º bank. (Just in case anyone reading this is not familiar with sport RC flying, the elevator actually makes the turn when the plane is in a steep bank. If rudder is used at all, it's used in the opposite direction of the turn just to keep the nose up. Indeed, some jets started coming out without any rudders at all, just fixed vertical fins. The AMA, I believe, now has a rule that functioning rudders must be present.)
So, I'd be interested in hearing what others have to say. Right now, I believe ArduPilot will give you either rudder or aileron, not both (correct?). If it gives both, it seems it would be based on a single, but mixed, signal. Would there ever be a need or benefit to having independent rudder and aileron control? I'm sure full-scale UAVs have this, but it might be a bit too much for an amateur UAV.