Hi marcelvdwart

No, I stayed with the twin elevator setup because I was curious how it would work out. I agree, it could be done with just one servo. I've got mine setup as ailevators tied to the ailerons thru the transmitter. They work great but take some getting used to. The OS FS 115a is a bit of overkill but it should fly like crazy. Some people complained that the control surface throws were too small but I have found them to be right on.
Don't forget the dreaded high speed stall the Extra is famous for. Too much elevator throw is the culprit for that. The sugested throw in the manual is perfect.

Good luck
Keith