We've sailed the Celebrity Millenium last year (our first cruise), and loved it! Gorgeous ship, elegant, excellent food, and we even had a butler who was happy to accomodate any of your requests (e.g. my 7 year old son absolutely felt like having a strawberry ice cream after dinner, but there was none to be had..or so it seemed, until I called our butler and he showed up with one for each of us!)
Celebrity attracts 30s-70s crowd in general, I think. We went during the spring break, so there were quite a few kids on board, but it didn't detract from the "casual elegance" atmosphere. They have pretty good kids program--keeps them entertained.
We're an active family, and generally prefer to do lots of land activity; but despite that, we're sailing on Celebrity Century on July 31! The whole experience on the Millenium was so wonderful, that we're trying it out again. I'm 99% confident that we'll love this cruise too. Celebrity keeps its ships spotless at ALL TIMES! I'm not kidding. I don't think you'll have any issues with their cuisine--it was just fabulous! (and we live in San Francisco Bay Area, where we've sampled plenty of fine cuisines--just so that you know we don't live on McD burgers all the time and have some fine steaks periodically).
Try Celebrity--you won't be disappointed!