Java, I had hitech 605s with a 645 on the rudder. Switched to JR and before long I started experiencing servo drift. With evey stick input the servos would stop slightly off center. I was constanly re trimming the control surfaces before I realized what was going on. Flip the sticks 2 dozen times and the elevators would be off by 1/16" 2 dozen more reps and they would be off by 1/8" etc. Switched to JR digitals. These things are sick. You can not appreciate digi's until you try them. As far as carbon vs 4/40 rods my choice was determined by the weight that I needed on the tail to compensate for the Saito 100. I go for useable weight when balencing. No "lead sleds" in the hanger. Joe