Unfortunately this is going to happen ANY iPhone 5 you guys get, whether it's original or multitudes of replacements.
Frankly I'm surprised Apple went and used anodized aluminum when it's common engineering knowledge that Al is a soft metal. The anodization is a surface treatment and any slight dent or ding to the surface will remove the anodized coating, letting the bright shiny aluminum show through.
It's an inherent design flaw in the body of the phone, even though it looks AMAZING, it's going to look terrible after a short time of regular use when the body gets all chipped up.
I saw a friend's phone last night, the edges were ALL chipped and shiny. Looked like the phone was 5+ years old, and he only had it for a week!
I'm treating my black phone with super careful kid-gloves till I get my outer case for it.
A protective case is the only way to protect these extremely vulnerable phones.
Operation-wise, I LOVE this new phone with i)OS 6. It's worked great so far.....and maps has been surprisingly ok.
Cheers!