The last several times we've gone, we have not been on any type of dining plan, mostly because it's just been me and DH (pre-kids). But we took our 3 year old DD in May and crunched the numbers at home. The dining plans just seemed like so much FOOD to us and I hated the fact that some dining took up 2 table service credits. So, we budgeted $1200 for food for the 3 of us for 8 days in Disney. We spent almost all of it, but, had we done the dining plan, we would have left with credits on the table. DD3 often shared meals with either myself or DH and I brought snacks from home to munch on. We still managed to eat at 3 character meals (all 3 breakfasts, which are usually the least expensive of all character meals). We don't feel cheated in any way and were glad we didn't have to have the hassle of keeping track of what credits were used and how many we had left.
Maybe in the future, when our kids are older and eat more (we also have a 9 month old DS) the dining plan will make more sense, but for now, paying Oop is the best option for us.