Also, it is the currently the only way to get 60% katara scrolls IIRC
You'll use all of the Nx skills (except maybe tornado spin). They're either VERY important for training or are required to upgrade other necessary skills.
You will not have a worthwhile Dual Blader without the Nx skills.
Spoiler!
Also, it is the currently the only way to get 60% katara scrolls IIRC
bolt202/veil225/feint200