We have done the Deluxe DDP for the past 4 years for a few reasons:
1. We've always gone during
free dining promotions and the cost to upgrade was minimal.
2. We are always traveling as a large party and it saved us more than doing the room discount.
3. The convenience of being able to pay over time and then arrive and have to deal only with gratuity was a lifesaver. No waiting for mom to hem and haw and try to order the cheapest thing on the menu or trying to split the bill and figure out which jerk ordered the steak and who only had a dinner roll.

4. I love a great meal and I LOOOOOVE Disney restaurants!
5. I am a planner, a list maker (can you tell?) and a rather meticulous person by nature. Having reservations made and meals taken care of ahead of time was huge (and you pretty much
have to in order to use all those credits to your advantage!). Never once did we have to suffer through ten people saying "I don't care, what do
you feel like?" as we're starving and it's 300 degrees. Reservations are set. Show up and shut up.
That being said, here are a few caveats:
1. It is a TON of food. We almost never ate the dessert.
2. You have to be careful about planning your meals or else you'll wind up running to make ADRs or getting caught up in too many meals, too little time for everything else.
3. I would never personally pay OOP for the DDP. In years past, it made sense; however, with the increase in price, it no longer makes sense to me. Again, this is personal and I don't care what others do.
We are staying offsite this year because the finances just didn't work out, but we still love Disney Dining. It made sense for me to buy an AP and a TiW card to get a discount on the meals we will have at the parks. Now, instead of cramming a ton of ADRs into our vacation, we have eaten at enough of the restaurants to have narrowed down our absolute faves. We're averaging 1 TS meal per day instead of 2 or 3 with the DxDDP. (or is it DxDP? I'm so bad with acronyms...)
We loved the dining plan when it was free/low cost to upgrade to the Deluxe. It gave us the chance to prepay for a lot of nice meals out. Now we just don't feel like we need it because we've experienced all we wanted to and feel very comfortable just going to the few places we really like.