The basic ground training, flying and landing is same. What is different is the takeoff. In hill flying you climb up the mountain with 12 to 15 kgs of equipment to the takeoff point. In winch based flying you spread your wing on the ground, get connected to the winch rope and you are pulled up to desired height. Wind pattern at lower altitude (height) in open spaces are more predictable. In winching, altitude can be controlled unlike in case of hill training.Fear is less; safety is more as you start at ground level on a flat surface.
You need more ground training for hill flying because the terrain and altitude is decided by nature. Risk factors are lesser in winch based training as height is controlled by the winch operator, he can abort the flight if pilot is not in command. Since the area of operation is open spaces, your takeoff and landing areas are chosen with no obstructions like trees, electric poles etc.
In case of hill flying duration of flight is extended by staying closer to the ridge while in winching you try to find thermals to gain height. This does not affect beginners as in both cases initial flying is restricted to understanding takeoff and landing techniques.
Training by winching has advantages as one can do multiple flights in one day. You do not spend time and energy to climb the hill for takeoff.