I like the Plaza for lunch if you are not in any huge rush. I do find with my little ones, they ge anxious sitting for lunch there when the rest of the MK is waiting for them to explore. Counter service we like Pecos Bill.
DH and I absolutely love going to the Plaza Restaurant for lunch as a TS.
We eat there once each trip. A cute victorian setting and relaxing.
Excellent sandwiches, not a horrible price, and good ice cream for dessert!
Although I can't really compare it to CP - never been there for lunch before!
Nothing wrong with Crystal Palace. I had lunch there and thought it was great. If a buffet/family style (Liberty Tree) isn't what you want, the other TS choices are Plaza and Tony's. Or hop on the monorail--which would probably net you the best food quality for lunch.
Pecos Bills is quite popular with my family. The combo meals are large enough to spilt. I don't like to have a large lunch like at CP or LTT because then all I want is a nap.
I would recommend Tony's if you aren't eating there for dinner one night. We have to eat there every trip on our last day to end the vacation at the MK! If you like people watching-ask for a table out on the patio and then you can get a view of people walking in and out of the MK.