I actually prefer a convenient off-site service such as Hertz because you can walk a LONG ways to on-airport cars. I like to get on the bus which is right outside the door and then be dropped off at my car. The Hertz facility is about a mile north of the airport property on SR-436 (Semoran Blvd). That's the road that goes straight north out of the airport property. It's still very easy to get from there to SR-528... the road to the port, and it's very easy to get back there when you return your car.
Aside to Horace...
...was Hertz still located at the Cape Royal Office Park when you used Hertz? They've since moved to another facility a few miles north, so they're only four miles from the port now instead of seven miles.