We just returned and were not on the dining plan. I liked the freedom to decide what we wanted to eat that day and not have to worry about it. Of course it all depends on how much you want to spend and how much you eat but I agree that eating counter service meals for most of your trip is not so bad. We ate 2 main (pricey) meals over our 8 days, dinner at the Hoop Dee Doo because it was highly recommended and lunch at Le Cellier in Canada because I love it there, we also did a character breakfast at Chef Mickey one day if you count that as a pricey meal. The rest of the time we ate when we felt like it and decided as we went what we were hungry for. A few days I was perfectly satisfied with breakfast from the hotel food court, a mid-day shared snack, and some sort of dinner.
The Sci-Fi also surprised me in price because we did that for lunch one day, each got sandwiches, sodas, and milkshakes for dessert and our bill was only about $50 including tip!
We also saved by buying a half gallon of milk (we lucked out on having a fridge) from the food court, which was a dollar more than the tiny individual cartons, a few things of cereal, and entenmans donuts. We spent less than $10 on that and had breakfasts for half our trip and snacks!
Hope this helps