Additionally, we like the peace of mind of having it all paid for ahead of time, even if it's not always as cost efficient. For example, on our last trip, we didn't get the plan and had car trouble on the way down that set us back $1000; we ended up cutting all of our ADRs but a breakfast at Crystal Palace (my kids were really looking forward to eating with Pooh) and spent most of the week eating as cheaply as possible at QS locations; if we'd had the plan, we wouldn't have had to worry about it. It's worth it to me to not have to worry about it.
See, here's where I have a hard time understanding, simply because it flies in the face of the way I plan travel. I understand pre-paying...in my case, I pre-save most times. I pre-pay my room (when needed), but often get a room only discount where I pay the balance the day of arrival. So, instead of paying so much per month to WDW, I put that same amount in my savings to pay for my room. Likewise, I set aside money ahead of any trip to pay for meals and for incidentals (and usually have more than enough funds in savings by trip time) just like I were paying toward the dining plan. Instead of paying Disney before my trip, I must pay myself.
A few days before my trip, I move those funds from savings to my debit card, and I use that debit card to pay for my room balance and for other things, such as food, t-shirts, beer, during my vacation. I usually over-estimate how much I need for food/beer/etc., so I have plenty of funds available (and I'm not stressed about meal cost as a result).
Beyond that, I've priced out the dining plan, and unless it's 'free', it's a huge loss given the way my family eats. We don't do character meals ever day (usually just one a vacation) and rarely do buffets, and we like appetizers and share a few deserts every now and then, but often don't get them. So the way I vacation, DDP would not save me money...and paying ahead wouldn't give me peace of mind, because I already pay ahead without the DDP (as I said earlier, I pay myself before my trip).
Still, even though I don't personally understand the 'I prepaid, so even if I happen to lose a few bucks, I have peace of mind' way of thinking, I can appreciate that it works for a ton of people who go to WDW, and prepaying for the DDP makes their vacation that much nicer. That's because I'm willing to pay more (a lot more!) for a WDW resort I like...because it helps my personal peace of mind in regards to my mood during vacation. I am not someone who regards a hotel room at WDW as a place to simply 'sleep and shower'...and *even if I did only sleep and shower in my room*, I'd still want upgraded amenities in compared to what values offer. I know some posters can't fathom why I spend a thousand or more above the cost of a value to stay at a mod or deluxe at WDW, but it makes my vacation nicer for me. So...even though I don't personally get the DDP 'peace of mind' way of thinking, I can totally appreciate that it works for others and works
great for them.