I have mine set up for flaperons. I have used them several times and my experience with them on all occasions have been other than good. It seems to throw the balance of the plane off somehow in my opinion. Yes the plane will slow down, you are adding drag. You will lose major aileron control and reactivity though, least I have. In my experience the plane tends to want to become sluggish and drops a wing. Good luck if you add flaperons to it. Flaperons may be good for some aircraft but I the you might be better off with regular flap setup for the nexstar.

Wes