I have poly in some areas of my 86 suspension, and they are noisy. They do stiffen and improve the suspension for performance driving, but may not be what you really want for the average driver. Personally I wouldn't install poly in any application that moved. Dogbone and cradle bushings would give a little more solid ride without noise, but control arms and sway bar pivot points could get squeaky. My sway bar pivots don't have lube fittings and they are very noisy at driveway and parking lot speeds, but I don't notice them on the highway. Poly end link bushings don't seem to present a problem and are of benefit to the sway bar.