You have decided to not rent a car? Will you be driving outside of Disney to shop/eat/sightsee? Meals on property can be pricey and you will save quite a bit by eating elsewhere for dinner. If you spend a lot of time in the parks, having lunch there makes sense but dinner could provide other options. We used DME which is run by Mears during a prior stay and had no issues. I believe they now offer a similar service but charge for it.