For us it wasn't. The deluxe was too much in January. We were very tired of food by the end of our trip.
If you're generally big eaters throughout the year, then yes, I think the Deluxe may work for you in the summer.
For us, I sent a text to a friend on the way home that said "As God is my witness, I'll never do the Deluxe Dining Plan again" (a horrible nod to Gone with the Wind on that quote

)
Our normal eating style that of a grazer. Smaller meals and snacks throughout the day. A typical day of meals would be a small bowl of cereal or a piece of fruit in the morning, light lunch and our big meal is dinner.
Generally speaking our meals took 1.5 - 2 hours, not including getting there or waiting 5-20 minutes to be seated. We always felt like we were waiting for a meal, eating a meal, or feeling full after a meal. I felt compelled to order the more expensive items because when running the calculations on whether or not we were coming out ahead, we weren't 'saving' the money I thought we would.
I also felt like I missed out on a lot of snacks that I love because I was too full to even think of a snack in the park.
The DxDDP works great for a LOT of people on this board, and I am sure many of them will post here how wrong I am, but I can tell you that in our party of 7 at Disney, not a one of them will ever do the DxDDP again.
The
DDP doesn't work for us because I like sitting down when I want to for a meal, and there is too much CS in the DDP for us.
Next trip we're loading a credit card with what we would have paid for the DxDDP and going to spend it eating what we want when we want. We anticipate using that card for quite a few souvenirs at the end of the trip because we barely broke even with the DxDDP in January.