My first cruise was on the Disney Magic (sailing as a solo as well), which I use today as my standard I judge other lines by. All in all I believe that the Disney ship had the best overall cabins (layout & size) and best officers and staff of any line I have traveled. The rotational dining I believe to be the best overall dining on any ship/line I have experienced.
Since my Disney cruise, I have traveled with Royal Caribbean, NCL, Carnival, Celebrity, MSC, and Princess. When I decided on a cruise line for my upcoming Panama Canal cruise with my father: it was an easy decision to save a full $5,000 by going on the Sept. 2013 Disney Wonder sailing, (compared with Holland, RCCL, & Princess). What's great is that my first time was in a balcony and for this cruise it will be a family deluxe balcony, which looks to be the same size as the mini-suite on Caribbean Princess.
So all in all, sometimes you can save money with Disney: repositioning & transatlantic!!