Garhauer Adjustable System
Here's why I like the Garhauer adjustable fairlead system or any system. i can't tell you how many boats i've been on where the fairleads look like they are rusted in place. What that means is the position they are in is like the broken clock which is correct twice a day. The position they are in is right for some particular wind condition and point of sail but wrong for all other situattions.
Secondly, sailors and for that matter all humans will do what is easy and not do what is hard. It is hard to adjust a fairlead car when the sheet is under power. You have to step on it to move the car and then there is the decision as to how many holes you should move the car. With the adjsutable system, which operates like a traveler, you can actually dial in the setting you want and as you move the system you can watch how the jib is reacting. With the pin type system your just guessing and you slam it any hole just to be done with it.
I would not be without and adjustable fairlead system.