If you're riding north from UPS, the feeling of things begins to change a bit. The wavy slickrock you just experienced will be replaced with ledgy sandstone punctuated by flowy trail. It's good to be on your toes and ready to react to frequent challenges.
LPS gets a little closer to the rim of the canyon (if you can imagine) so keeping your eyes on the trail and not looking into the distance is another added challenge. The ledges, coupled with sharp turns and the occasional drop are good motivators to be on your game through this section.
LPS eventually gives way to the two track of Porcupine Rim Road and the start of one of the most famous trails in the world.