It's not the springs it's the short arms (angles) and your shackle angle that are making the ride rougher than you expected. I assume you bought shocks through them too - those should be good. True you just installed Heavy Duty springs on your vehicle but that is why you bought them... isn't it? Unfortunately there is a lot at play when changing the suspension and you'll need to do more research on how to improve ride quality. Changing the springs isn't going to do much, fixing your angles will.

I removed a leaf out of my RE 3.5 leafs and it helped a ton. I think it was the 3rd one up. Also helped level it out since the rear sat too high. I though the front rode pretty good though.

I love mine. I have angled fixed lowers and stock upper and it rides really smooth. Do you have stock arms?

i'm surprised to hear this. i have rode with RE 5.5 extreme duty superflex kit with drop brackets for years and it rode just awesome. i eventually removed the drop brackets and control arms and replaced with staangs fab long arms. i didn't really notice a difference in ride quality. that's just how good the RE kit was, compared to long arms. i eventually removed the springs and installed 8 inch coils and 5.5 inch leaf packs (the 5.5 kit comes with 4.5 leafs and shackles) and 2 inch shackles.

i agree, loosen the bolts, let it sit on it's own weight, then tighten them up again.

my other cherokee has an RE 4.5 inch kit, and it rides great also. the rear is a little stiff, however. but swapping the shocks to bilstein would help tremendously.

You need more weight up front or new springs, control arm drop brackets, shackle relocation boxes.

RE 3.5" springs like a lot of the 3" springs have a very high spring rate @~240lbs where stock was ~150lbs. RE is also known for giving more lift than advertised and making your control arms at a steep angle. Stock these arms are almost parallel. Shackle relocation is an upgrade to any XJ and dramatically improves the rears feel though it may take some adjusting to get it right.

RE 3.5" coils are rated for 240lbs, I went with superlift 550s 4" lift with 160lb and the ride is much smoother and no more coils dropping out on the trail from too much flex

That is strange. I read your original post a few days before I installed my RE 3.5" Super Ride and was worried. But mine seems to drive fantastic. Although it could be because my old springs were inverted and causing me to have very limited travel. It would hit hard on every little pothole. Now I can aim for the holes and barely feel a thing.

what shocks are you running? ive ran multiple sets of RE coils from 3.5 to 6.5 and never had a rough ride issue with them. in fact they have almost been to soft for my liking.

I have the 3.5" RE lift & Bilstein shocks on mine. Rear sat up a bit when newly installed but settled in nicely. Ride has mellowed too. I think it rides quite well for a lifted Jeep.