We've had some terrific meals at some WDW venues, returned and had a really "off" meal, often due to poor service. There are a couple, however, which have been less than stellar more than once:
1) Pizzafari: terrible 3 times. Like eating in a Chuck E Cheese's with more noise and worse pizza. Thankfully DS no longer pleads to eat here.
2) Ohana: twice the service was more than rushed, with all the food piling upon us at once. The second time I was prepared, asked them not to deliver entrees until we had finished appetizers, and then sent the entrees back when they appeared anyhow. The "cousin" both times got huffy. DS has food allergies, and their dealing with him was more reluctant and obtrusive than almost any other WDW place.
3) Mama Melrose: rushed, impatient service twice, with difficulty dealing with the food allergy in a gracious way. Hit or miss food, mostly miss, althought the flatbread is very good.
4) Le Cellier and Chefs de France: we seem to have about 50/50 luck at both places. A couple of times they've been outstanding. A couple of times inattentive, with food not to order specifications and far too long between server drive-bys.
5) Marrakesh: one very good experience and two bad ones. Both of the bad ones were server related and close to closing.