It all boils down to how you want to eat. We prefer the deluxe plan at this point, because we enjoy sitdown meals, don't care for counter service, and do a lot of signature dinners. We're not breakfast eaters at all, but the deluxe plan is very flexible. We'll made a couple of character breakfast reservations for the kids, but for the most part we skip breakfast, have lunch as our rest/break from the heat & crowds in the parks, and then have a very nice dinner in the evening.
The breakeven point on the deluxe plan is about 2/3 of the credits used for TS meals (including signature dining). If, like us, you use it for 2 sitdown meals per day and end up using most credits for TS, it can be an excellent deal. We love the flexibility and the all-inclusive feel.
The main downside to the deluxe plan is that two sitdown meals per day does take more planning so that you're not spending big chunks of your time traveling to your dining reservations, and those meals do take time away from rides and attractions. We don't find it to be too much time spent eating, but others do, particularly those who are traveling with kids who need a break at the resort in the afternoon (my kids don't do naps/breaks, so we just go all day - a sitdown, air conditioned lunch is our break!).
And some people complain that it is too much food, but it has been our experience that you don't have to order every morsel that is included for the plan to be worth its price. We often skip or share desserts and still save money.