We've only cruised Princess and DCL. We have one of each currently completed- and 2 more DCL cruises upcoming!
Food- pretty much a tie. We haven't eaten in the adult restaurants such as Palo yet, on either line. Princess had a better and larger buffet area. DCL had better poolside food. EXCEPT- Princess has Ultimate Balcony Dining, which is a private dining experience you can book. The most romantic meal of my life.

On our balcony at sunset in Cabo, 6 courses, champagne, wine, flowers, a photographer to come take pictures of us! And the pictures were included!! The server literally waited outside our room door for us to finish a course, run down to the kitchen to get our next course. Amazing. And only $100 for both of us!!
Rooms- oh my gosh, hands down DCL. We had a balcony room on Princess that had to be half the size of our cat 10 on the Wonder. Really. And with the separate beds, split bath, and privacy curtain, it made sharing a room with our kids pretty comfortable. On Princess the extra 2 beds would have come down from the ceiling OVER our own queen bed! YIKES!! I would be beyond claustrophobic!!!
Service- we had far better servers on DCL. But a better stateroom host on Princess. Not that our DCL host was bad- we just never saw him. Everything was always tidy. But on Princess he went out of his way to pop in, ask what he could do for us, be sure to always have fresh wineglasses in the room for us, etc. Overall the friendliness of the CMs on DCL was superior.
Entertainment- DCL wins easily.
Pools- pretty much a tie. DCL's actual pools were better, but Princess had those nice padded loungers on Deck 10 and poolside were nicer loungers than the ones on DCL. The DCL ones reminded me of ones in anyone's backyard.
Price- ay yi yi- DCL just keeps going up. We have cruised very cheaply on the Wonder and upcoming on the Magic. We've been able to cruise off season and save money, and get SPH rooms on top of that!
DCL is hands down our favorite. It has been a wonderful balance of adult activities, kid activities, and things for all of us to enjoy together. I dragged my DH on the first
Disney cruise and he is sold, sold, sold. It does help that we are big Disney fans in general.
I am curious what 2011 is going to look like, price-wise. We are planning an Alaskan cruise for 2011 with friends for our girls' 8th grade graduation. They have several Princess cruises under their belts. I don't think I'll be able to sway them to DCL (if indeed they go to Alaska) if the prices are so much higher than on Princess. If we go the Princess route, we'll get balcony rooms for the adults and throw all the kids in the inside cat room across the hall.
