Well if your personal itinerary is to get up and go to a different spot to sight see every day, then renting a car might make sense. But if you're only taking 2 or 3 trips away from your hotel the whole time you're in jamaica, it's just cheaper and easier to grab a cab for a trip. Plus, the roads aren't marked the greatest I've noticed, so having a cab driver's knowledge of how to get to places is valuable as well.