To mention little of the potential causes of hygiene issues onboard, we were advised by medical staff to be quarantined to our rooms after consulting them following our children's vomiting and diarrhoea starting from our second full day aboard. While in-room movies were comped, it wasn't exactly our idea to board a cruise ship only to watch movies in the cabin. We had to miss out on the shows and specialty dining that had been pre-booked and paid for. Room service was only free if ordered from their "Gastrointestinal Diet" menu of broth, gruel, and steamed vegetables, and otherwise chargeable even for adults who had to stay in to care for the sick children. It gave us the feeling that the cruise line was simply trying to keep a lid on potential bugs from spreading, at least until the cruise was over we were off the ship and no longer their problem. IMO they're not doing a great job at that by relying on little more than the affected passengers' sense of public courtesy (to outweigh their desire to enjoy what they paid for) to remain in their cabins.
While good value if executed consistently with the concept, our experience with 'The Key' priority service is inconsistent - both embarkation and disembarkation were disrupted either by being directed to normal queues or having our group split halfway despite identifying ourselves as Keyholders. It was also difficult to determine how to access other 'The Key' services.
The Royal Caribbean app, while novel, is unreliable as the personal schedule is unable to keep up with the various meals and activities that were signed up for and/or cancelled along the way.