Do you autocross ? Have you mod your car, such as lowering it, buying bigger wheels ? If so, go with the adjustable struts. Go with the non-adjustable struts if your car is all stock and you don't want to spend more cash for the adjustable struts.
My first car was a 67 Mustang Coupe, 2nd one was a 67 Cougar XR-7, 3rd one was a 66 Mustang Coupe. Why did I get rid of these cars for ? I know why, because I'm stupid, stupid, stupid.
My next Ford.....