Main XHB is split up with Directional buttons on LT and Face buttons on RT. WXHB has all the important buttons that you will press on the RT this includes you pot, with healing skills/healing potions on the LT. the Expanded XHB has same skills on both configs and has your AOE skills and de-buff skills plus Limit break.

This setup has a smooth layout that make pressing all your buttons with little stress and with great flow. For 7.0 you can see  Zanshin replaces Ikishoten after using it so you don't have to change the layout to accommodate the new skill. And since Shoha and Shoha II are one button it also frees up a place to add either a role action skill or something else.

Hope this helps

asura.x