I/ve had th 4.5" for three years now. started out too short eye-to-eye dist. had to add extended shackle to let them flex and get the eye off the front of the rear pocket. I then removed the shortest leaf and replaced it with the stock short leaf to help them settle more. after a couple months the shackles were in the correct orientation and the springs were starting to ride amazing. just recently, i took out the middle leaf and replaced it with the stock middle leaf. this made them even softer...soo soft..i love it. they're now even with my front 4.5" Re coils with 5/8" spacer.
I say, if you want to bolt some springs on and leave it...go with RE, or another. I went the cheap way and tuned them to my liking. it can be fun. and its good practice at removing the rear diff.
wouldnt recommend them if you plan to tow. I haul about 80 lbs of subwoofer and what not, a 90lb rear bumper, rocker skidds. when all packed up(with people or gear), the jeep sags in the rear. for a DD, i like it to float like caddy.