I haven't done anything in either for a while, but from memory, in world editor, you can really only delete and place lots plus a few trees and such. You can't change the land any, for example, if you have some land at the side of the road that is too steep, you can't flatten it in the editor, you would need CAW for that. Same goes for terrain paint, if you wanted to change the land from grassland to desert, you would again need CAW.