Actually...I measured the travel, linkage and spring movement (posted around site somewhere)..and the X's rear suspension does not go past flat fully compressed,

...with lift shackles...it gets almost flat, but you'd need more than just another 1.5" of wheel travel to get the leaf to reverse arch, the condition that IS associated with damage over time....mostly on extremely lifted leaf sprung jeep CJ's, etc....

...not really a true concern for X's which pretty much do not have more than a 3" lift at most.

As Gbizzle mentioned though, even a stock set-up fatigues with time.

As to functionality...

The ~ $150 AAL adds height, adds capacity, stiffens handling, steals flex....

The ~ $50 shackles add height, do not affect capacity or handling, and add flex.



Essentially....an AAL makes sense for those who do not off road, and the shackles make sense for those that do off road.

Obviously, its not like an AAL can't off road, its just that a shackle will work better...so individuals merely look at their priorities, and choose the option that works for them.