I am planning on picking up a 5 due to a great deal. However in the event that it runs out, I am looking at the 5c. How does it hold up against scratches? I prefer to use my phones without cases (I did so with my first gen and 3gs iPhone, which only got slight superficial scratches), but I am somewhat obligated with my 4s and I imagine I would be with the 5. The 5c however is plastic, does it hold up? It would introduce and interesting factor into the equation.