The jib tracks allow you to adjust where the tension will be, which affects the sail shape for the conditions you are sailing in, and the point of sail that you're on. Kind of like saying, how does the position of the rudder look? Depends on if you're going straight, or turning port or starboard. When the sheet tension is on the leech of the sail, the jib car is forward, this pulls more on the leech of the sail for pointing, and you get the whole sail in a nice curved shape. Now, let's keep on the same point of sail, and the wind picks up, and the boat is healing more, and your First Mate's eyes are looking concerned, as you move the jib block back, the tension now transfers to the foot of the sail, this will allow the top of the sail to twist and spill the air off the top portion of the sail, which takes away some of the power, but also helps to ease the healing of the boat, and stops scaring your First Mate.
Like Luke said, depends on how you intend to use the boat. The previous owner was obviously a serious racer, and set the boat up for his preferences.
Hope that helps......
Don