We had traveled on Royal Caribbean in 2012 (repositioning cruise from Miami to London), and enjoyed the cruise, very much. This 2018 cruise, we were celebrating my one-year survival and almost no evidence of disease (cancer).
On board, the rugs were stained in the halls and our cabin; tablecloths were stained for two meals. Glass windows and portholes were grimey. As obaumlackl wrote, two elevators were out of commission the entire cruise; two worked sporadically. (Should never happen!) Bad news, especially for disabled persons. Food in Windjammer was, indeed, mediocre and repetitive; breakfast and dinner in Sapphire Dining Room were a little better and service during dinner was great. We, too, thought that more local foods would be served. Of course, we could have lobster if we wanted to pay a great deal extra.
Of our ship-arranged tours, the Boston tour (in the Steps of Paul Revere) was a disaster. Little pertained to PR and Revolution; most was a Chamber of Commerce welcome tour to Boston (during the rain). Eight hours of this!
I have no idea if we were a 5D, 2D, 3D, etc. -- we just had an ocean view balcony. The carpet was stained and the glass on the balcony doors was dirty.