Stephanie,
More and more often I find the
Quick Service Dining Plan is more appealing to many guests. As long as you budget knowing that it is far from covering your whole dining expenses for the week, it can add the flexibility that you describe.
The advantages over quick service meals are obvious. You spend less time dining, so you have more time riding attractions, watching shows, and generally being out there having fun.
As for switching a Table Service dining credit for a Quick Service one, I have two key points. First, if you are going to do that you are really killing the cost savings point of the Dining Plan. You would be far better off simply not being on a dining plan at all. Also, officially you are not supposed to switch those credits, so you will probably not be able to turn a table service credit into a quick service one anyway, though sometimes cast members do allow it.
Write me back if you have more questions!
Have a magical (and delicious) vacation!