I fall into that catagory of people who use both the DDE as well as the DDP. I have to sit down, each and every trip, and figure which way is going to be cheaper. Usually, they come out pretty close. I tend to go with the DDP even if it's about $50 more..it's just so darn convenient. But, if they deleted the tip from the mix, then it wouldn't be so close in cost.
Same here! I like the DDP just for the convenience. I don't like to carry money around and love knowing that everything is paid for in advance. However, if I had to carry money for tips, I'd go ahead and use just my DDE card as the savings are about the same. In fact I'd probably order less (no appetizer to go with that dessert--just one or the other).