Le Bistro is excellent..if you have an adult only party and are looking for a fine dining experience, choose Le Bistro. It is one of the best kept secrets as far as disney restaurants go, well, not such a secret, it books up very quickly, lol. Le Bistro, is very small, quiet, intimate restaurant. The service is the sit back and relax between courses type of service. Plan on spending a good 2 1/2 to 3 hours for the meal.
Chefs is also quite good, just different. Much quicker pace, family oriented, you probably only need about an 1 1/2 hours for you meal, depending on how many courses you order.