I like the refillable mug coming with the dining plan now.
If we eat in the food court we use one of our quick service credits. For the drink we get a bottled drink and then fill our mug to eat and then again when we are leaving for the bus. We bring the bottled drink with us for the park. (I bring a ice chest back pack to the park. Since I use a
scooter no one has to carry either their mug or the extra bottled drink. They put it in the scooter basket.
Any other time we eat at the resort and go back to the room we fill our mugs and bring the drinks back to the room. That way we don't have to buy from the vending machines after the food court is closed.
In the past (before the mug was included in the dining plan) I would buy the mug based on where the soda machines were at each resort. For instance it is easy to pass through a Value resort food courts on the way to the buses.