We prefer dinner over lunch. Last summer we did both (back when lunch was still a FP), and found lunch to be loud and hectic, and it was hard to find a seat.
The food at lunch was good, though, in particular the steak sandwich, the roasted pork, the master's cupcake and the strawberry cupcake.
Dinner was another animal altogether! It was so calm, quiet, and relaxed! Our server was great, and not just with us, I could hear her interacting with the other guests around us. She did not have the same canned, rehearsed spiel to deliver to each of us, and was just very pleasant and knowledgeable about the restaurant. Everything we had for dinner was amazing: DH's steak was cooked perfectly, my salmon was incredible, oldest DS had the dinner version of the pork and LOVED it, youngest had the kids fish of the day and was very happy. We did not have dessert with dinner, but DH and I both had a beer. After a humid, rainy day, it was a nice respite.
We were seated in the West Wing for both meals. I was glad to be there, because the rose is such a treat to see, and I love how the portrait changes when the "storm" starts outside and the lightning flashes. I do hope we get put in the ballroom next time though! During dinner, the Beast makes a pass through the rooms at varying times, and when you finish your meal, you make your way to his library where he greets you and takes a photo with you (that goes on your memory maker).
We have both lunch and dinner booked for this trip on the same day, but I made my family pick one, and every one of them chose dinner as the favorite, so we'll be having dinner there again on our last full park day. We also have a breakfast booked there for our first MK day of the trip as well, and I'm excited to see how it goes
If you're really interested in having a meal there, just keep checking. I see posts about additional reservations becoming available quite frequently. Good luck and have fun on your upcoming vacation!!!