To me, I think it highly depends on the type resorts one likes and the locations. The Grand Mayan / Grand Bliss / Grand Luxxe in Riviera Maya, Acapulco, and Nuevo are mega resorts focused on luxury rooms, luxury pools, exceptional service, and high end golf. The GM in Cabo is much smaller but a mega resort is planned there. There is continuing construction to make the grounds spectacular with regards to grounds and gardens. I am assuming there are other resorts that are similar in focus but I think the Mayan system is exceptional.
I perceive the Royals as a different breed altogether - largely Cancun based and a more traditional timeshare approach based primarily on continuous upkeep of the property. From all accounts, they seem to be excellent, much better than average, on maintaining the property and customer service. I am assuming there are also many resorts that fit in this breed but with lesser quality.
For us, we prefer the mega golf style resorts that are continually innovating and adding new stuff - part of the fun of it all from our perspective.
Different strokes for different folks.
Mike