Location Hierarchy vs Location Superior

In my last tenant, we had lLocation Superiors... much like sup org. We assigned people to the bottom level.

Now the same data has been turned innto a Location Hierarchy. Our location constrained security seems to stop at State and doesn't move down - it's as if its broken at the state level. We have states with more than one location so we need to split them out (Local Office). We can't assign any roles at that level. I also can't assign a superior to levels now.

Things are just working the way I expected to see them. So what is the difference between Locations Superior andocation Hierarchy? Why would I use one over the other? I need your guidance before I go to the implementors. What is the impact of changing the structure?

Thanks...we are one week post go live and all the bugs are showing up.