MOST people use ball-locks. It is easier to use, since you ont need a special tool to unscrew the valves, AND stores will sooner supply ball-lock valve equipment before pin locks. When you go to a contest or something, you'll find that about 90 percent of people are ball-lockers.
The pins stick out from the base of the in and out posts. A socket won't fit directly over them like on the ball lock kegs. You can still use a regular wrench, I believe. The "special" tools are really just a socket with notches cut into it so it fits around the pins.