Roundhouse kick striking areas

The roundhouse kick is used in many martial arts and is probably one of the most used kick there is. Its quick and can be very powerful. Another reason why it is used a lot is because there are different surfaces on the leg that can be used for striking. Thai boxers tend to use the shin for striking, as it can do the most damage. A shin kick to the thigh is like having a baseball bat wrapped around you. In other martial arts the top part of the instep is used. Its not as powerful as the shin but there is less chance of your opponent grabbing your leg as with the shin, and can be used in a jab like fashion. Personally i like using the shin when kicking to the legs and upper area, but i think when kicking to the midsection, the ball of foot is the most effective. Its a very awkward kick to defend as its small point of contact can thrust through peoples guard delivering a different kind of pain. To understand what i mean try tapping your ribs with your fist, then with just one knuckle. Do you feel the difference? Any views?