We have eaten at Bistro around 6 times. In all of these trips, have only seen one table with children and these children were probably around 8 and 10 years old. Bistro is not on the dining plan, does not have a children's menu. Therefore, the patrons here are usually people enjoying excellent food as an evening out rather than trying to get a good deal while taking a break from the parks. The dinner is pricey but well worth it. We always get very dressed up and plan on spending a couple of hours here.
IMO, except for V&A, Bistro has the best food and the best adult only atmosphere. It's a small dining area, the waiters are in tuxedos, there is wine pairing available. The service has always been top notch. It's a place where you do not feel rushed and you aren't in any hurry to leave because it's quiet and romantic.
The cuisine is upscale French. Chefs de France, on the other hand, is more rustic French. Chefs will be packed, noisy, full of people (including children), tables close together. The food is more of the plain and hearty fare.
The only similarity between these two places is that the wait staff will be French.