I have been doing Dinner by Design for a year now, and given our family situation it is perfect. I've also attributed weight loss to making healthy selections from their menus (they provide all the nutritional information for you).
My husband works LONG hours. We live on the south side and I work on the north shore, so by the time I pick up my child I'm not home until 5:00 at the earliest. I get up at 4:45 am. By the time I get home, I am so exhausted that preparing a meal is the last thing I want to do! Chopping vegetables, measuring spices, using a tiny bit of an ingredient that will only be used once, AND having to clean up the kitchen...well, I'm willing to pay a bit more for the convenience of not having to do that. I come home, pop dinner in the oven, cook it on the stove, or grill it, and it's done.
I get the 12 meal plan and half size everything. Basically that means that I get 24 meals a month, so I cook 6 nights a week and then on Saturday we do pizza night. The cost for my 24 meals is $240 or $10 a meal. You get 3 servings in a half meal (3 pieces of chicken, fish, etc.). It's built-in portion control - you're not stuffing your face or overeating! I usually serve the meal with a vegetable, salad, and fruit for dessert. For our family, it is enough food but we do live in a society where people are used to 'super portions' and expect a gargantuan piece of chicken, so I can see how DbyD would disappoint some.
I usually do my sessions on a Saturday morning, and quite frankly, would never take my 2 year old son. First of all, this is kind of 'my time' and secondly, some months it takes me well over 2 hours to assemble the 24 meals. I can't imagine my son being patient or attentive during all of this.
For my family it is a matter of convenience. To me, it seems only slightly more expensive to go the DbyD route. It also has cut down on the "I'm too tired to cook, let's just go out or order in" which is definitely more expensive and definitely less healthy. I want to eat healthy food that tastes good, is 'fuss free', and has little to no processed food involved. I also make my selections based on calories, sodium, and cost (I typically keep in mind the $10 it costs to make a meal or $3.37 per entree). The rotation of meals is such that we only eat a particular dinner 2-4 times a year!
I've gotten a few sides but our family didn't like them. They also seemed to be overpriced.
Please feel free to send me a PM if you have more questions. As a working mother who rises with the chickens and doesn't get home until later, this has been a perfect option.