We've done 3 DCL cruises (1 Bahamas from PC, 1 Western Caribbean from PC and 1 Port Canaveral from NYC), 1 Princess (Alaska), 1 Royal Caribbean (NJ to Bermuda) and 1 Carnival (charter specialty cruise from Miami to Western Caribbean). So we are not experts by any means, but since 2016, when the cruise bug bit us, we've tried a few things. We are a family of mom, dad, 2 teenagers, 1 tween and grandma.
Guest Services: IMHO, Disney has the best guest service. Everyone of the other ones were lacking when compared with Disney. On our most recent RC cruise I had a question and called Guest Services from my stateroom. The phone rang and rang and rang. I counted and it rang 63 times and then I was disconnected. This happened twice. Folks working in Guest Services on Princess were not friendly or particularly helpful.
Entertainment: Disney's Broadway style shows are hard to beat. The shows on Princess were a hot mess, but the comedians and other performers were top notch. On RC one of their shows were terrible, but the other one (We Will Rock You!) was fantastic. Their comedians were funny and they has some great bands/performers in the bars and nightclub.
Food: Disney has the best main dining rooms IMHO. But the food and dining rooms on Princess were also very good. We especially enjoyed our meal in Chops. Well worth the $50 upcharge to us.
Stuff for Kids to do: My teens and tweens still love all things Disney and meet and take photos with the characters. But none of them use the kids/teens club very much. RC had an amazing array of activities for them: rock wall, indoor skydiving, surfing simulator, bumper cars, rollerskating, ping pong, air hockey . . .
If I were ranking them I would say: 1. DCL
2. RC
3. Princess
4. Carnival
When we choose which line to sail we look at itinerary first, cruise line and then price. We also consider how much time we plan to spend on the ship. For DCL is worth it if we like the itinerary and the price isn't totally ridiculous. For Alaska. we couldn't justify the price difference when 2 inside cabins on DCL cost 2 X as much as an inside and a mini-suite with an huge balcony on Princess. We found that on a Alaska cruise we just don't spend enough time on the ship to worry justify the cost.
Last November we sailed from NYC to PC and had a day at WDW and one at Castaway Cay. We can't think of a better way to spend Thanksgiving week. Sadly they are not doing that cruise this year. We are hoping that DCL buts this back on the schedule form Nov 2020.
I guess the answer for us is: for the right itinerary and the right price DCL is totally worth it to us. If money were not a consideration, I'd sail them everywhere that we could. But, sadly money is a consideration. We sailed DCL first and my friend's wife said that we are spoiled. This maybe true, but we really enjoyed the cruise on RC and will also be sailing them again in the future.
I hope this is at least a little bit helpful!