The dining plan isn't for everyone. Luckily, as mentioned above, there are a few plans to choose from too. You need to assess how much you want to eat and time sitting down at restaurants, too.
My family did the dining plan 2 years in a row. The first year we paid for it and did not receive any room discounts, either. The second year we got it for free. The first year gratuities were included and the second, no more. (Not sure if it is true or not but I heard they put gratuities on because the quality from the servers was not great because some didn't care because they were getting their tip from Disney whether they perfomed good services or not) Each time we did the dining where we had one snack, one counter service and one sit down per day. This worked out well for us. We always wanted to sit at one meal and relax(usually dinner and a couple of breakfasts), while the other meal could be a quick grab (usually lunch) and we brought cereal from home and had cereal and milk in our rooms for breakfast. (This saved us time since we are not morning people)
Take a look at all of the options out there and decide which would work well for your family.
Tip--our fav restaurants are O'Hana, Chef Mickey, Crystal Palace, Whispering Canyon, Le Celier, to name but a few.:slurp: