I have camped at Fort Wilderness three times now and highly recommend it. We have camped in an RV, never in a tent or in the cabins. I like the atmosphere of the campground. It's rustic, but has all the amenities that you need. My oldest daughter was four when we camped there last and she LOVED it! She rode the ponies, watched peacocks all the time, visited the Frontier Grocery Store, etc. We took the boat to Magic Kingdom, which was a treat in itself. In fact, it's our prefered form of Disney transportation from the Fort.
Disney bus stops were easy walks from our campsites. Bath houses were very convenient, as were dining options. There was a wonderful buffet available all three meals as well as the Hoop De Do Revue which is a dancing/singing/dining option. Chip and Dale were on hand nightly for Disney movies shown outdoors in an ampitheatre setting (complete with marshmallows to roast!)
Camping is an inexpensive option for staying on Disney property if you have a camper or tent. However, the cabins are the same price as the higher end Disney accomodations....so unless you have a family to split a cabin with, I'd stick to the camping.