We're using the DDP (basic) in April and I'll let you know how it goes!
We had it in December 2003 and it worked out really well. At the time, tax and gratuity and an appetizer were included and 2 of my 3 kids were still 'kids'. This time, no appetizer (which is ok with me really), and all of my kids are considered 'adults'
(DD is 10 and still eats mostly chicken and fries when we go out!) and I have to remember to save for Tax and Tip before we get there.
I do like knowing it's already paid for though!