I do both. For 20 years my buddy and I stay at casa mexicana and when I come down with my family we usually do park royal. AI bit we still get into town as well easy enough. I enjoy both.Way too much hate on this forum for AIs people have never stayed at.
My one comment about the Iberostar, which I have stayed at, is don't view them as black and white - AI or in town. Stay where you like and if its an AI have a night in town or two and take a taxi.
Honestly, as someone who mostly stays in town, I crave the simplicity of a quick stop at a buffet some nights.