The rudder on a 4* doesn't really lend itself to "coordinated turns"- this has been noted and discussed in several discussion threads. It tends to bank the plane like a trainer and also causes the nose to drop. In fact the plane designer (Bruce Tharpe) made changes to the tail design to eliminate this effect when he released his Venture 60 which is otherwise a very similar plane. That being said, the rudder does work well for snaps and spins, and it is very necessary during takeoff!

My advice to anyone moving up from a trainer to a 4*- don't worry about using the rudder during flight until you get used to the plane, then give it a try.