Like thecampingman, we've been enjoying SW Florida for years. We're in Bonita Springs which is closer to Naples than Fort Myers. Our choice of parks is
Imperial Bonita Estates which has more activities than any other we have ever experienced -- or you can take the more relaxed route as many others do. Traffic? Sure, but one can quickly learn the alternate routes that don't involve US 41 or the interstate. (Be sure to watch the movie in the link.)
A search of my posts will reveal a listing of parks from Fort Myers to Naples, or PM me and I'll email it to you along with a note or two of which ones to avoid. Put "IBE" in the subject line to avoid my spam folder.
On edit: SW Florida parks are on 3rd page of my posts 12/24/12.