The main difference is a lot more pad work, at full power. To build the power you must have good technique and be very consious of correct ditance. Bagwork is an effective way to work on punching power but it is a bit limited when it comes to kicking. Very good for fast, powerful, single kicks.
What are the main differences between Combat Training and Assaut Training? Is it mainly more heavy bag training and harder sparring? Obviously Combat is more common in France and I am intrigued to know what sort of training they do.