They will last alot longer than rubber bushings. That is the main reason I bought poly bushings. I noticed that my front end felt a little more tight than before, but I had also changed out my upper A arms, tie rod ends, shocks, and now lower ball joints. I don't have a single piece of my stock suspension (front and rear) left on my Expy, except for the lower A arms, but the ball joints fixed them anyway so it is basically like a new truck now.