We try to go at "off" times. Late at night (okay for me that's like 9:00) they tend to be crowded with people coming in from the parks. First thing in the morning they are crowded. We tend to go to the food courts at the hotel mid-day when taking a break. I'll bring the kids to get a snack while they do homework. If we are there during a peak time, we'll usually order a pizza or something.
I would think that they probably have the same food. Pop's is bigger and is usually really crowded during breakfast and later at night. But the lines move pretty fast and they usually have lots of registers open. They have a pretty large refrigerated section in the back as well.