I find it is kind of hard to judge by looking at a picture. If I were to do this, I want to see live samples.
*BUT* in absence of real samples, am in the camp of... trust Apple's taste. I have a 4s, I think it's the most beautiful gadget ever, and of course am not going to cover it with bumper/case, it's naked, and radiates its beautiful lines, it reminds of the Monolith on
Space 2010.
But OK some people don't want to have the same thing as a few million others, so a little customization, perfectly reasonable. If I ever to that, I would engrave my last name in script on the outer metal band and leave it silver and not do anything to both glasses as they are perfect as is.
For the 5, I really have no opinion. There was a reason when given the choice, I picked the 4s over the 5 despite all the advancement, A6 blah-blah.