I have the dual fuel model of KitchenAid you've got pictured. I've been using it for a year and a half and love it.

We find that we use the upper most of the time. It's nice because it heats up very quickly. There is an oven light button on the controls that you can turn on and off. The light on only when you turn it on and you really can't see much inside when the light is off. I've attached a pic so you can see...the racks are visible but that's about it.

My top is stainless and I think it looks as good as it was when it was new. I'm a messy cook, but a little stainless cleaner and it's as good as new.

I think the blue enamel coating inside the ovens doesn't serve any purpose but is just the coating KitchenAid uses.

Hope that helps!