Chicken Guy. Maybe it was the victim of high expectations, but the tenders were tough and flavorless. They apparently have 20 sauces because they are necessary. Mac n cheese was very good, so I would consider going back for that, but I'll stick with pizza or burgers for DS QS.
The other only bad meal I've had was a burger at the Pop Century food court, which I only ate because I was taking a midday break when it started downpouring. It was just bad, and the reason you need to be very picky around Disney burgers.
I've only been to BoG for dinner once and I loved the experience. The escargot, steak, and desserts along with the setting were worth $65. They did bring out my steak quickly, but the waitress realized I wasn't quite done with my app, apologized, and brought it back later. I'm sure they feel the pressure to turn tables but it wasn't a big problem for me.