I recently went back to Civ4 to play Rhye's and Fall mod, something I didn't do before. Civ4 is such a welcome relief than the restrictive nightmare Civ5 is. I loved having the freedom to build a road any damn well place I want to without worrying about costs. Or the freedom to build any building I want. Or the freedom to put units any place I damn well feel like (except mountains and marshes, but it can't be perfect)
Civ4=freedom. Civ5=restrictions.