Another big difference between the two regions, Chablis and Cote d'Or, is flavor. Even a novice can taste a Chablis and a Cote d'Or white Burg and easily taste a difference. Chablis (e.g. les Clos) can be very crisp in style, lighter on its feet, but it can still have weight to it. The flavor profile tends to be tighter, in those I have tasted. They have a leaner feel to them. Don't think that lean is bad, sometimes you need a razor sharp white wine, it is especially good with food. Côte d'Or wines (e.g. Corton, Montrachet, Meursault Genevrières) can be bigger wines with a lot more weight to them, more expressive and open. The difference comes from what was mentioned above, Chardonnay itself hasn't a strong personality itself, but is like an actor, and the role is determined by the winemaker. In Chablis, there is little new oak, and lots of stainless steel. The wine is fermented and aged in a neutral environment, and so the leaness of the Chardonnay grape comes out. However, the grape is very structured, so you get this lean wine with a lot of stuffing. Further south in Cote d'Or, more new oak is used, the grape allows the Oak to make the wine expressive and big, and the structured nature of the grape helps support that weight. It is ironic that the grape has so much structure on its own, but it has a great plasticity that allows it to be expressed in many different forms. Sort of like the Madonna of grapes (not the Catholic lady, but the Material girl turned Vogue turned Évita, turned Hard Candy electronica style), you love it or hate it, but you can't fight the fact there she has a lot a talent, and has expressed it in many different ways over the decades, just like a Chardonnay.