I've been doing some research on the Keys, and think I may head over to Bluewater Key RV Resort next year. Excellent reviews on rvparkreviews.com - and the pictures look great with lush vegetation. There's a 26' minimum on your rig though...
[SIZE=1]Michelle & family
[COLOR=Blue] 2005 28' International CCD
Leo's campground was not much to brag about and not on the water but it is the most reasonable one we found (other than the military bases) and the closest one to Key West. If you are just sleeping there, go for it!
SC Coastal Unit