For us, it depends on how early we arrive, and how late we stay on check out day!
If we get in late, leave early, we don't have time to eat all those meals/snacks! DDP works best for us, when we check in early, and stay late on our last day (which is what we are doing this trip)!
We will likely have snack credits left over, only b/c we get extra full from the desserts (that we normally wouldn't get if paying OOP) so we have little need for snacks.
One mistake that I won't make again is paying OOP for a "cheap" snack (like a 1.99 yogurt) and saving up the snack credits, b/c I don't end up using them and then scramble to buy candy/cookies to take home, etc. No matter how cheap the snack is, I'm using a snack credit this time!!!