Wood or Concrete?

I need to compare and decide between two methods of constructing a 6' x 12' second floor balcony onto a cement townhouse. My limited knowledge of construction tells me that while the cement(4" thick) is cheap, the need to construct a frame with a bottom and four sides to form the floor, a chicken wire and rebars to hold the cement floor together with installing 4 posts would take longer and cost considerably more than just building three PT wooden braces, nailing 2" x 6" by 12" pressure-treated boards to the braces and nailing the 4 posts to the floor. Please tell me I'm wrong.