My wife and I took our honeymoon aboard the Allure of the Seas on a 14 night back to back (eastern and western Caribbean) cruise. It was our first cruising experience(and first real vacation as well) We're going to write this review from the point of view of a paleo/gluten-free/dairy-free couple so that others with similar dietary issues can get a good idea of what it's like. However, before we get into that, let us just say that the ship itself, the amenities, the clubs, activities and such were all amazing. I personally really enjoyed the rock climbing wall, the numerous bars and clubs and the plethora of hot tubs. Others have written here extensively about those aspects of the Allure though, so we'll focus on our unique experience.
On to the Gluten free/Dairy free situation. My wife and I went paleo/primal about a year and a half ago, around the time we discovered her allergies with gluten(not celiac, proper allergic reaction). Since then she has also found through elimination trial and error that dairy is not so kind to her either, though not as an allergy, more of a sinus congestion issue. I myself attempt to stay as Primal as possible, but it's not critical for me. So as we approached the vacation, being able to stay gluten free was a must, dairy free was more of a bonus. After speaking with our travel agent and RCL staff on the phone, they assured us that our dietary needs could be met.
We have to say that overall, it's true, they can accommodate just about any special diet, but that comes at a cost(not monetary, but time and choice). The main dining room on the ship is your best bet on ease of getting food choices. You can get the same wait staff each night which makes the experience 10 times easier for dinner. At this point we have to give a shout out to our waitress, Mary Jo, and our head waiter Memish(we did my time dining btw). They were PHENOMENAL and went the extra mile every night we were there to make sure she didn't have any contamination or issues.(The second half of the cruise Memish was in a different area then Mary and he still came back over to check in on us and help out if there were any issues). If you have a dietary need, ask if either of them are on your sailing and ask to be seated in their area when you arrive the first night.
The cabin with a balcony was excellent. We don't have much to compare it too, but being able to walk out and look out over the sea was very helpful when the ocean got a little rocky.