This tool, just as any other, can be found along the path Window > Panes(Tabs), where you can open any window available in the Daz Studio. Powerpose is a tool that introduces the user to a click and drag interface, where you can change positions of different elements of your character.
The genesis 8 daz figure has a superior pose that takes less place and is easier to work with.
The first thing anyone should understand is that each subsequent generation of Genesis is an improved version compared to the previous one.