per Bill's web page: "Benefits include a smoother ride, 3/4" per side narrower track, tighter turning radius, a full 6" of wheel travel,
adjustable travel limiters, and easier ride height adjustment than standard coil-over systems."
It is probably that at a cost of $1500 more than the standard Alterkation not too many people were ordering them. There are a few small benefits.
1) progressive spring rate
2) lower unsprung weight
3) packaging
Basically some of the reasons Chrysler went with the design in the first place. The question for me is if it is worth the extra money.
I have also read somewhere that the Caltrac suspension really wants a front suspension with 6" of travel, the coil overs only provide 5.5". Does it matter? Don't know.
I would like to hear Bill's input on the topic.