The place that modelers have the most problem with a Cub is they tend to apply power too fast, and end up torque-turning and losing control. (some will say its really "P-Factor' doing it... the result is what counts.)

Apply power slowly and smoothly and the taildragger will behave much better. As you gain proficiency in coordinating rudder and elevator to keep the tail straight (a bit of up elevator to hold the tailwheel down till you have a bit of airspeed) you will find you can apply the power faster.

Trike gear trainers let you get away with slapping the throttle to full. A taildragger won't let you get away with that unless you know how to deal with it.

Cubs have a slightly narrow landing gear. You have to be careful about doing turns on the ground at speed.

Cubs with scale control surfaces are subject to severe "Adverse Yaw" which can cause you to drop a wing and spin the airplane on final approach if you don't use the rudder for lining up with the runway. Using the ailerons at low speed can have the Cub turn the opposite of the desired direction. This tendancy can be reduced by setting substantial "differential throw" in the ailerons (more upward deflection than downward) but the real cure is to learn to properly use the rudder. The adverse yaw can be severe enough that with full rudder and aileron to one direction... the airplane still turns the opposing direction. (I used to demonstrate this doing landings with a Kadet Sr equipped with barn door style ailerons.)