We loved it and highly recommend taking your kids at least once! We stayed at Fort Wilderness Resort in our RV. If you have one or access to one, Fort Wilderness was awesome. If you can swing it, the cabins are very nice too, and sleep more than the typical resort room. They also have kitchens, letting you cook a little to save on the cost of food.
FW is a very short boat ride to the Magic Kingdom, and a slightly longer, but not out of line, bus ride to the other parks. We were able to come back to rest and eat lunch on most days, only eating lunch in the parks twice. We also planned dinner out twice, and had our own food the rest of the time. There is so much to do in FW in the evening that we ate a quick dinner and enjoyed some of the entertainment in the campground (campfires, marshmallow roasts, sing-alongs, movies, wagon rides, etc.).
We also planned our park visits to take advantage of the Magical Hours (available only to resort guests). There were no lines during these times and we could do the attractions multiple times at once.
The Unofficial Guide, mentioned previously, was a huge help with planning as was Mousesavers and Allears.net. Enjoy your trip!