Carl K.
Yelp
It's interesting to read the various reviews on several sites, from one star to five star. They all describe Cayo Costa more or less the same but the reviewers have very different reactions. Cayo Costa State Park is a pretty natural experience, for better and worse. That means you get the sun, wind, stars, meteors, sunsets, surf, sand, odors, heat, sweat, insects, dolphins, birds, manatees, tortoises, snakes, raccoons, spiders, etc. that naturally exist in a place like this. If you love that, CC is 5 star. If you love your comfort more, it's less than that.
In my opinion, the park has just the right level of amenities, which is not much. This is not a resort or mall. The screened cabins can be sultry and sticky but we slept ok. We used insect repellent but still got pretty bitten up, so ok we itch for a few days. Running water at the minimal rest rooms is nice to have. The tram works well but only runs once an hour, so plan on it or take a nice 3/4 mile walk. Boat access is limited, so plan on that also and take what you need but not a lot more.
Do your homework to know what to expect. Bring what you need and not a lot else. CC SP is beautiful and pristine, which is hard to find. It's not controlled and comfortable, but that's not why we go.