It was our first time trying the dining plan and we got the QSDP for our 4 night stay but used it for almost 5 due to a late flight. I did my homework thanks to the Disboards and Disney Food Blog and including the cost of the refillable mugs, I calculated a $555 value for the $420 cost.
We mainly shared meals, brought meals back to the room for breakfast the next day and used our alcohol options. The best deals were Wolfgang Pucks, Polite Pig, D-Luxe Burger, Flametree BBQ, La Cantina de San Angel, Satuli Canteen, BOG shared breakfast and Oasis Pool Bar. Best snacks were the F&G booths, Jambon at Les Halles, a Mickey pretzel and sundae at Plaza ice cream.
At Sunshine Seasons we bought a meal to go which they wrapped up for us, but had to open the bloody Mary. So, we just poured it into our mug and brought it back that way.
The pool bar , Polite Pig and Wolfgang's were good options even including a tip for the servers/bartenders. All in all we were very pleased with the plan, ate really well, and even had credits on the last day to bring back snacks from Goofy's.