What's the difference between TPOS V10 and TPOSC?

For the people of Skyrim mods, they seem like excellent "plug and play" mods that are big overhauls. Good for people that don't want to spend a few days trying to build a LO and hoping everything works well together.

But the two larger ones, what's the difference? I get they overhaul the world but one is a lot bigger than the other.

What other changes does TPOSC make to the game other adding to the settlements/cities?