I don't think you have anything to worry about. At least the dealer is taking care of it and admitted they chipped it. I would rather have a dealer do it and match the paint as close as possible then some indie shop. I did read somewhere that the paint quality on our W210's was far below par of the previous years before the body change. I have little nics from driving if I look carefully and I nicked it myself by swinging the door open. Not too bad at all and because of the location the dealer told me if they touched it up it would be mire noticable. At least you are getting the whole hood done.
I bet it will look better then it did before the chip happened!