I have seen them fly with both the split rudder and non split rudder and from a flying stand point, didn't make much difference. I did fly Chip's with the split rudder a couple of weeks ago and the rudder authority with the mini 9650 servos was unbelievable. It had as much rudder authority as any plane I've ever seen and the knife edge loops Chip did last weekend at our contest here in TX were as nice as I've ever seen. The 2 mini servos definitely work, but only with the split rudder. I don't know if it is because you are only moving 1 half in a pulling motion, but it is very impressive. Not 100% sure it is necessary, but it does work...

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