I think that Bistro de Paris has a quiet, romantic atmosphere in general, but there may be more disruptive customers there, since it is located in a park. When we went, it was very quiet and dimly lit inside, until a baby started screaming and then its mother walked by, wearing what appeared to be her string bikini - no shirt! Then another table of kids was seated, and they ran around, blowing candles out at the other tables and generally getting in the way of the waiters who were doing semi-dangerous things such as lighting crepes suzette.
But it may be that we hit it with a bad crowd, b/c the restaurant for the most part seemed pretty quiet, and it had a view of Illuminations, which was an added bonus. Most of the customers there seemed to be adult customers, or at least families with well-behaved children, except for the two I've mentioned above.
The food was spectacular - much better than we've ever gotten at Chefs de France. Andy did a review of several restaurants that we went to, if you search under posts by amw5g.
Another good restaurant was Citrico's. This wouldn't be too expensive, if you split an appetizer, each had your own entree, and then either split dessert or got your own. It also had a view of fireworks, and it was even quieter than Bistro. When we went there, there were only maybe 6 tables of people! And this was in early August, so we thought everything would be pretty crowded. I think in general, the resort restaurants tend to attract people who dress a little nicer (i.e. actually wear tops to dinner) and if you go a bit later, like we did (8:30 pm), then usually the kids are mostly gone, so it's fairly quiet.
Jiko was also pretty quiet, but I did not care for the food there at all (inaccurate server answers to my questions, bones in every bite of my bass filet), though Andy thought his meal was okay - not memorable, but okay. I will say in Jiko's favor that it was dimly lit, very quiet, and not too expensive at all, so you may want to give it a try.
Cheers!
Heather W