I just did the Warrior spring shackles, and I am very happy with the results. It maintained the ride quality, didn't seem to add any unwanted rear end shimmy or unstableness and got my truck back to even ride height. I can tell you that I almost grabbed my Glock and started firing rounds of .45 hollow points at my truck when I had a bolt that refused to come out of the old shackle, but a truck that is 11 years old and has 130K miles on it I had to expect some difficulty. The other 3 weren't too bad, but the top bolt on the driver side was a MOTHER F#@%^&$%!!!! Took almost 6 hours and a couple of busted knuckles, but I eventually won, and was able to retain the original bushing without starting a rubber fire. If anyone is interested in what I went through and how I finally got it out send me a PM and I might even make a post about it if I get enough interest.
Short story long.....I am happy with what the Warrior shackles did and the price was good compared to some of the other options.
Edit: I should add that I didn't have the "pimp lean" off to one side. It was level side to side, just had "dat saggy butt" to begin with.