Well, if you are speaking of South Florida it would be Hallendale in my opinion. I think if it is a matter of cost, the Hallandale real estate market is fairly low priced and there are still condos and co-ops that are almost striclty senior. Some are over-55 buildings, but that restriction has been easing lately.
I am sure there i sa demographic study to find out the scientific data, but I do think that seniors are a large part of the entire landscape in Florida, as many came here years ago before the real estate boom and were able to stay because they own their property outright. Aventura has many seniors, I believe they are just a hgher income bracket of seniors. in Aventura.
I woud be glad to answer in more specific terms if you wanted to know how it specifically relates to real estate, as in an investment stadegy for you as to where to purchase.