We enjoy traveling by ship so that we can unpack once, have a/c in our rooms (unlike most of the European hotels), have a great selection of food and entertainment all the time, have medical facilities onboard, know that we are a priority for the cruise lines (unlike booking in certain locations and hotels separately). We do not have the headache of car rentals and knowing which side of the road to drive on, and we know what to expect for the optional tours booked through the cruiseline (they have done the research and know what their customers want to see and do)--these are just a few of the pluses.
We have traveled several different lines (Carnival, Disney, Viking) and really enjoyed the Princess cruiselines for the 2 cruises we have taken with them. (We also did the Alaska land and sea tour out of Vancouver with Princess.)
The 2 ships we have been on did have facilities and activities for children and teens (i.e. the teen room, swimming pool, sports center, etc.) but seemed to cater more to the adults, which we appreciated.
Kept very clean by our room stewart. The closet space was great, and we appreciated the extra sitting room, storage areas, and tv (which could be closed off by curtains if one of us wanted to sleep). These cabins need more plugin areas. We requested an extension cord which we used daily. (We always travel with our own nightlight to plug in the bathroom so that we do not have to leave the bright light on all night.) The extra room in the bath with the bathtub/shower combination was also appreciated. Would like to see the balconies a little larger on the newer ships though... We were on the Baja deck which, although further away from some activities, was a quieter deck without restaurants, pools or entertainment located nearby.