I feel like I should answer this question since this was us last October. The problem is, I'm not sure how to answer it...
We're in our late 30's (well, I am; my husband is 41) and have a 7 year old son. Our first cruise was the Magic in May 2012, then we did the Wonder in September 2012, and then the Fantasy in September 2013. We had the Magic booked for the Southern in October of last year, but moved to the Jewel when RCI did the kids sail free. We were sailing with my parents and were able to get a 2-bedroom suite on the Jewel for $2500 less than the 2 rooms on the Magic. Plus we were concierge and had the perks that went with it.
Overall, we had a great cruise but it wasn't the same as Disney. That being said, I'm ok with that. Disney got us hooked on cruising and now we cruise to see places we'd never be able to see otherwise. My mom at one point actually said "there's no wow factor on this cruise". I thought that was amusing since RCI's whole selling point is WOW. The adults had fun in the casino (both my mom and I left with an extra $500 in our pockets!) and the kiddo had a blast in the kids pool and on the kids slide. It's NOTHING like the Aquaduck though! We also found family activities lacking. I think because the Jewel is a smaller ship. But we did enjoy some trivia in the atrium and even went to a talk on Kincaid. We didn't go to any shows, but my folks went to one and said it was great. I later read someone's trip report that said that was the only show worth seeing. Most of the food was good, but nothing was spectacular (in our opinion). We did love having the buffet available for dinner. The pastas at the buffet were always really good.
Our room steward (is that the right word?) was better on Jewel than any we had on
DCL. We did have the same servers in the dining room every night we went. There's no "rotational dining" and we sat at the same table every time we were in the dining room. The servers were not as "in your face" as the DCL ones. We like that, but others like to form lasting relationships with their servers. The room, being the 2-bedroom suite, was awesome. Having a separate living room was so nice especially since there were 5 of us in the room.
I think the main thing that clouded our trip was a hurricane caused us to miss St Maarten and we were really looking forward to our excursion there. We also were able to dock at St. Croix but power was out on the island so all excursions were cancelled. We wandered around the port area for a little bit (they had power for some reason) and then got back on the boat. So I think we went on a "port intensive" cruise and ended up with too many sea days. (side note - the captain took us way out of the way of the hurricane and we had the smoothest cruise we've ever been on)
I don't know that my rambling is helping you any. I suppose what you think will depend on what's most important to you. We wanted to be away as a family and to see new ports. Our kiddo still calls it his favorite vacation and I think that's because we spared a room with my parents. I still really want to cruise Disney, but I don't think I can justify the expense any longer. We looked at the Magic to Norway on opening day and it was just over $7000 for 3 of us in a balcony room. We decided to try NCL and have a slightly bigger room, the Ultimate Beverage Package, and the Ultimate Dining Package all for $3300. We're using the difference to go to Disney World in the fall.
If you have any questions, I can try to answer them...