That's an EXCELLENT link. I don't ever use pull-pull. Well, not NEVER, but I avoid it for the most part.

I usually put my rudder servo in the tail, because I use larger engines, and I'll use a single push/pull setup. Or use 2 rudder servos in the tail and rig them both push/pull.

I didn't know why people used offset horns and how the geometry all worked with straight or offset arms.

Very informative.