I have not been on RCI yet, first cruise in April 2019. However, I have been on Disney 5 times, 3 Magic, 2 Fantasy. I have also been on Carnival. I am glad to hear all the things about RCI and the comparisons. My daughter doesn't seem to like the kids club, but that is just her. We went when she was 3 and 6 and would rather spend time with us. She did enjoy certain things about the club. We are not one to force her to go, unless it was when we wanted to go to Palo(Disney's specialty restaurant).
Some things I can tell already are different between the 2 lines.
1. Website - Although the booking of excursions maybe harder, finding information about the boat and actual layouts of the staterooms is much easier on Disney.
2. Disney includes soft drinks in their price
3. RCI Price is much better, I am getting a Grand Suite for $3000 less than an Inside Stateroom on Disney for same week, plus an extra night. However, I will have to pay for Soft drinks. So, to make prices comparable, if I include soft drinks on RCI, it is still $2500 cheaper.