Also as a bonus we have the weirdest take from...obviously our very own AlphaDefence
Powered-JDAM uses a more robust airframe like structure that wraps around the bomb body to better handle all the forces as opposed to regular JDAM-ER where the wing kit is attached using hardware store like hose connector. Moreover given the fact that it has a turbojet engine and fuel tank, the overall length of Powered-JDAM becomes almost double of the Mark-80 series bomb it's attached to.
And also 80km is pretty much the range of a regular JDAM-ER; for powered JDAM it's almost 500km.