It works very well. The hardest part was figuring out ways to control it and not getting carried away with too much flex. I used to have swivel-type shackles on the axle too, but that ended up allowing way too much movement. And I now run an XJ mainleaf with the really large bushing. It flexes great and provides some resistance as well.
I didn't actually build my setup. It was built by Roggey Enterprises in Placerville Ca. I would have built a 4-link X. Mine is actually a 3-link with some strange geometry. Works good and it has proven to be really strong.
I have tried 3/4 elliptic a few times - years ago. I agree, they suck.
The reason that they dont work very well is that they give too much feedback when under throttle. They allow the rear axle to wrap like crazy even with stout traction bar. They have an uncontrolled droop to them as well, almost as scary as the revolver shackles. They were a liability on the trail, as I found them to be the weak link not once, but twice on the Rubicon. The front kit that you can buy from MORE is two fold wrong, as I learned to dislike the Shackle Reversal also.
I swapped in some f150 rear springs in the rear of my jeep and put waggonneer fronts on the front. Solid mount one end and use a shackle that is long enough to tap into the usable travel of the leafsprings. I have not seen a more reliable setup, and it sure flexes enough.
Somehow missed this thread. Sorry to jump in late but I agree with the rest of these guys. I ran 1/4 elip for about a year and went through a lot of different setups trying to get it right. I finally gave it up and have been much happier being back to leafs. 3/4 elip just gives crazy flex and crazy axle wrap. once your axle is so far down the force is starting to push up instead of forward, combine this with a decent tire size and the torque will just wrap your spring up like a watchspring.:rotfl: Even with a good regular leaf application you better plan to deal with the axle wrap. I currently am running some re-arched YJ springs in the back and waggys up front. If you reposition the shackle so your getting full use of it you can get plenty of flex.