I have installed energy suspension front end bushings in one of my Cadillacs. I greased the dog siht out of them during install, 10,000 miles later they squeak terribly. I was living in eastern north carolina at the time so salt air and sand intrusion might have been a factor contibuting to the squeaking. It did make the front seem firmer, then agian the original stuff had 115k miles on it. I can't stand to drive the car, the squeaks are so bad. Next year i'm going to pull the front end apart and replace with Moog rubber OE design parts. I'll NEVER install poly anything unless there are no alternatives.
I recently rebuilt the front end on my Malibu using Moog OE design parts. All bushings, ball joints, tie rods, pitman arm, center link and sway bar bushings. The original pieces had 93K miles on them, the only thing that needed to be replaced was the center link, the control arm bushings didnt look bad at all, that was the hardest part, pulling apart the upper bushings. The car feels great, nice, tight, firm and no squeaks.
Durability wise I'm sure the poly stuff will be longer lasting, but I doubt i'll be able to put 50,000-100,000 or more miles on any of my cars to make it worthwhile. Better handling or response, I doubt it the rubber and poly between the inner and outer shells is about 1/8", I really don't see that compressing so much as to make a difference. Just my thoughts.
