I do believe that if you take care of your Le Creuset Dutch oven, it'll last you a long time. Mine are 20 years old, though I don't use them every day, of course, so I'm not much of a test subject. I think, though, that with really heavy use the enamel interiors might degrade and become less slick. I read somewhere that you can have them reenameled. Which is probably expensive.
But like you, I prefer a light interior to a black one. Gray would be okay, but I think black would take some getting used to.
However, I HATE glass lids. They're way too heavy, and of course they may break.