My wife and I have only traveled on two lines, Cunard and Disney. This means our fellow passengers have ranged from the older and dressier crowd to the younger pirate-clad crowd! We have felt comfortable on both and enjoyed ourselves with few reservations.
We do, however like to up-charge for the extra attention and added privacy. On Cunard we traveled Princess Class and on the Dream we travel in Concierge. We have found Concierge Level on the Dream fits our need for additional quiet spaces.
We do not have children and we still love traveling DCL. What we have found in researching other lines is that we do not need a casino, we like cocktails but not "party drinking," we do not need a disco, zip-line, rock wall, or surf pool. We understand our fares "subsidize" children's spaces we will never use but on Oasis of the Seas, we would be subsidizing all of the above and have no interest.
We frequent the underutilized bars, lounge on the concierge sun deck, attend ship tours and lectures, read in the Concierge lounge, visit the adult's only pool, and travel to the adult's only beach on Disney's island. We also do love Disney, and that helps. We take in the 3D Disney movies, enjoy the Disney/Broadway shows, love all the free Disney movies on our stateroom TV, and point with glee at the Disney characters roaming the chaotic lobby.
Negatives. Sometimes it's the parents not controlling their children. Sometimes it's the children. But as a general rule, we have found the kids to be very well behaved at dinner, like young ladies and gentleman. Where do they tend to get crazy...the kids' pool. But, if you don't visit the kids' pool it quickly becomes a non issue!
We loved our stateroom. Wish it had more outlets, but we keep forgetting a multi plug! The split bathroom is a very helpful feature. On our last cruise we adored our stateroom hostess.
The dining staff is always attentive and friendly. We enjoy seeing them at meals and they make us feel welcome.
I can go on, but there are plenty of fantastic reviews. Wished to give perspective from guests without children. We sail again on the Dream in less than a year. Our third trip on this ship.