Our experience has been this.
Our first family trip was when the kids were pretty young (almost 4 and 6 1/2) during January 2002. We stayed at Homewood Suites in Kissimee. Since the parks closed early and the kids were young, we headed back to our hotel for dinner almost every night. We would have a late afternoon/early evening snack in the parks and then late dinner at the hotel (although I must admit, more than once the kids either fell asleep on the way back to the hotel or they were too tired to eat!). We had bagels and fruit, mac and cheese, or DH would go out and get pizza or subs. And pb & j was always an option! It saved money as well as precious park time and it worked out well us. We had free bkfst at the hotel every day, which was perfect for us, and we had lunch in the parks (mostly counter service... not to be cheap, but just to save us time). We did have a lunch at RFC at the AK and CRT bkfst one morning, and lunch at Planet Hollywood at DTD once.
Fast Forward to January 2004....kids are older now, but park hours are still short. We did stay at the HS again. (We were very happy with both stays). Again, we had the free bkfst, but this time it was a full bkfst, including eggs, bacon, sausage, as well as the usual, bagels, pastry, fruit, cereal, and juice. We had this every morning except for our CRT morning. Since the kids were able to handle more park time, we did some park hopping, so we were in the parks more hours. But we did still have a late dinner at the room at least once (we left Epcot before Illuminations because we were too cold... grabbed McD on the way back and ate in the room). We mostly kept drinks and snacks in the room. It was very handy for that.
Not sure what we will do the next time. I'm tempted to stay on-site (haven't done that since our honeymoon in 1992!)... but the kids really like the Homewood Suites and I like the "spreading out" room it gives us, plus the option of using the kitchenette if I want to. Guess we will have to take a family vote on this!
HTH..................P